I would argue that it is already the case that cheap cars look and perform excellently, compared with cars produced fifty years ago. They are more reliable, economical, comfortable, higher performance, superior in virtually every respect.

The other factor to consider is the use case. Something like a Ferrari is not reliable compared to a VW Golf, it sucks at carrying passengers and cargo, terrible fuel economy, it is horrible value for money and inferior in most ways apart from one - compensating for a small penis. That is its chief purpose and it is supremely well crafted for this use case.

Source: automotive engineer of 25 years.

Firstly: Designing an appealing sports/luxury car is expensive and many companies hire skilled professionals from known design firms to help accomplish this. The design often comes first and much of the car is constructed to fit the aesthetic and theme. Cheaper vehicles are more utilitarian with a more “that’ll do” attitude instead of being designed with artistic intention.

Secondly: Almost ever car maker has their own luxury brand or subsidiary. Selling cheap luxury/sports cars would undermine their own brand’s prestige and market segregation. There is a reason why dedicated luxury brands will not make budget-friendly vehicles unless legally forced to.

Fancy body on a cheap car.

Add big displacement and you’ve got yourself a Dodge or some of the Fords.

Additional trivia: The worst car I ever owned was a Ford Sierra. I absolutely hated it, but it sometimes got me from A to B. I seriously considered attacking it with an angle grinder and a welder. It already both looked and performed like shit, why not at least make it look cool? I joked about giving it an exterior looking like Mustang.

Lots and lots of reasons.

I’m basing this on your comparison of normal cars to currently existing exotics.

Predominantly: The vast majority of people don’t want an exotic car. They want to go from home to work and the store, maybe a drive for a leisure trip. They’re boring. They want to get their stuff and people in and out of the car easily and conveniently.

Exotics do not do convenience well. There’s minimal trunk space, there’s space for only two people, often “snugly.” They require some contortions to get into and out of. Think of how out of shape many people are and see if they fit into a highly contoured, reclined, and snug race seat and can crawl in behind a scissor- or butterfly-style door with a very low roof.

Engineering-wise exotics are expensive, both for the manufacturer and customer. Those compact, low, aerodynamic bodies on exotic cars take a lot of work to pack all the mechanicals in along with having to design a body that is crash-worthy for each new style. On top of that, they’re often mid-engine, which means a lot of specialty parts like transaxles, and wildly different handling characteristics than the average consumer is used to when you shift weight to the back of the vehicle.

Manufacturers stick with the “boring” designs because they’re based on existing engineering that is safe, requires minimal cost to make the new iteration, aerodynamic, fuel efficient, and has proven to be sellable to consumers. Profit is king. They’re not going to take chances on crazy styles that may not sell because again, people are boring.

I know people are going to chime in about mundane cars in production today that have some of the features I mentioned and treat them as an exception that invalidates the opinions I’ve offered, but the point is that if they were economical and profitable designs in an exotic body they would be more widespread. “You could just take “x” engine and transmission and build a “y” around it” argument.

I would suggest maintenance is a potential cost problem, too…some exotics literally require the car be split - the entire rear of the car containing the engine and transaxle removed from the rest of the car for access because of the compact engineering and inaccessibility to some wear parts. However if Toyota made a low-buck supercar looking commuter car I’d hope the maintenance would be cheaper and easier.

So there you have it. Cost of design, engineering, and maintenance. Boring consumers, convenience, and safety. Affordability and profit. That’s why we don’t have exotics everywhere. The market has determined that the few Halo cars we see like the Supra or C8 Corvette, or even the Mustang, is all the market will bear.

Because when they do, they start charging more for them. cough Kia/Hyundai

You absolutely can slap a Lambo body on anything (provided it fits) and there is a literal cottage industry that exists around doing so. It’s not popular because, let’s be honest, it’s pretty silly, and everyone involved acknowledges its pretty much just for fun and entertainment. The status symbol of “owning a Lamborghini” goes away forever the second you start the engine.

There is a lot of psychology that goes into designing the appearance of cars. Like, an extreme amount. Car companies spend millions designing and refining body shapes and styles, and building brand images, and pushing commercials that seed these ideas into your head about their brand looking a certain way and that look therefore implying quality, they’re connecting all those dots in your head, one marketing campaign at a time, and it works because we’re honestly pretty gullible creatures at least when somebody wants to spend millions upon millions of dollars researching exactly how they can weasel their way into your brain.

And this might surprise you, but the same “looks incredible but the worst piece of shit ever” can certainly apply to luxury vehicles. Aside from notorious reliability and repairability issues, Lamborghinis don’t usually win any races either. They won’t win a drag race, they won’t win an oval track race, they won’t win a rally race. They’re fast, certainly, but they’re not the fastest and for what you pay for a Lamborghini you could build a much, MUCH better purpose-built race car. You could probably build 10 purpose-built race cars. Hell, people build race cars out of junkyard parts that can beat Lamborghinis. They’re not the end-all-be-all of cars, nor are any of the other luxury brands. They have some nice features but they also have a lot of dumb features and yes, a lot of cut corners too. They’re designed to be desirable and profitable, not to be the best.

So to answer your question, it absolutely IS the case for cars, in fact it’s probably even moreso the case than it is with computer parts. Unless you really need to roar down the highway towing a 10,000 pound trailer at 80 mph and still get up to that speed in 5 seconds flat, you really only need like probably 30-50 horsepower max for most of the daily driving that people do, but people’s driving habits and attitudes would have to change and they would hate the feel of gradual acceleration, so they would simply never buy such a car. I think we really underestimate how incredible even the cheapest “crappiest” cars are. We’re talking about machines cheap enough for almost everybody in our society to own, that can drive at high speeds, in perfectly dry, climate-controlled comfort, carrying many passengers and cargo, in almost any weather short of a tornado or flood, with excellent reliability for hundreds of thousands of miles, that provide constant lighting and electricity and entertainment, all while maintaining a high degree of safety for the occupants.

If you’d rather putter around on a riding lawnmower with a Lamborghini body kit on it, you absolutely can do that, but you have to understand that once you start comparing the limited features and abilities it provides you will quickly find what you’ve constructed is the real “piece of shit” in comparison. Just don’t forget your slow-moving vehicle sign!

If you make a Toyota fancy, you end up with a Lexus. If you make a Honda fancy, you end up with an Acura. If you make a Volkswagen fancy, you end up with an Audi. If you make a Nissan fancy, you end up with an infinity.

I would like to mention manufacturing. Mass production of body panels. Those sleek looks may come at a cost.

Another thing is kit cars, basically get a chassis and replace body panels. Lawn mower engine…

https://en.m.wikipedia.org/wiki/Kit_car

Because it’s not that easy and a fancy car looks fancy because it’s a work of art and every detail counts

https://en.wikipedia.org/wiki/Hofmeister_kink?wprov=sfla1

I think our 2021 Honda Civic Sport looks pretty fancy. No one is going to mistake it for a Ferrari, but I think it’s pretty hot for the price.

I also wouldn’t fit in any real sports car anyway.

They want to “reserve” features looks and styles for expensive cars to make you upgrade.

Isn’t that what Scion does?

but why don’t manufacturers of basic cars just put a fancy-looking exterior onto them?

“Kit cars” are a thing…

Not sure what’s popular these days, but for a while people were putting Shelby Cobra bodies on Miatas.

It’s way more than a Miata, but way less than an authentic Shelby.

So people who just care about the looks have been doing this for decades now.

But when it happens as a production, people don’t buy it because other people recognize it for what it is, look at the PT Cruiser.

So if a couple people do it, it passes as expensive. If a lot do it, it comes off as tacky and becomes a joke.

Some companies spend a lot of money on market research and trying to get ahead of trends (Mercedes Benz, Honda, Toyota) some companies disregard common sense and do what they want (Alfa, The French in general) and cheaper brands dont waste the money on price point cars. Its not an Iron clad rule but people buy a german to project wealth, you buy other euros to project style, you buy Honda and Toyota for reliability. You buy a Nissan Altima because they will finance you, you buy a Chinese car because you arent keeping it past warranty expiry anyway.

As to what sets them apart. Little things like painted brake calipers, the quality of the badging, the texture on the plastic interior, little trim pieces that stop you seeing any of the interior workings, the windscreen wipers looking “chunky”. Wheels and stance also play a large part of the image. Wide wheels simply look more expensive, as do lower profile tyres.

Then things get a little more tactile, the dull thump when you shut the door over the higher pitched clank, the thickness of the interior plastics and number of fasteners making the interior feel sturdier even though you cant see the difference, the sensation of the indicators being put on, the UI on the touchscreen…

Prestige brands also dont do trim level names/badges very often. They like letters and numbers like 330i M-Sport or c65 AMG. Lexus followed suit with the LS400. They WANT you to say “Yeah, I got the Touring package” or “I bought the AMG sports pack” and they know their owners want to do it too.

why don’t manufacturers of basic cars just put a fancy-looking exterior onto them?

They do. This is exactly what Hyundai does for the Genesis brand.