No Stupid Questions

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!