There's certain designs of cars that are gone and that's probably fine: traditional town cars and gigantic-doored coupes with opera windows, for example. But there's certain classes of cars that have died out, but maybe it's time to consider a resurrection. I'm talking about a very specific type of fun car.
I'm not really sure exactly what to call this category of car, because I'm not entirely sure it ever had a specific name. Sometimes they were "lifestyle" cars, sometimes they were casual off-roaders, sometimes "beach cars," sometimes, they were just fun cars. It never seemed like too much effort was spent deciding exactly what to call the class of car, much like how nobody seemed to labor too much over any aspect of the car. And that's what made them so great.
Here's the basic formula: a company would take one of its most popular, mass-production cars — usually a smallish, cheap, basic transportation economy car or similar utilitarian vehicle, and then produce a version that used essentially the exact same platform and mechanicals, but with a very stripped-down, ruggedized, usually open body style. Then, more often than not, they'd paint them all kinds of bright crazy colors. And that's pretty much it.
The result was a car that used proven, common, economical drivetrains, but with bodies that would allow the owner to do pretty much anything. Much of the interior trim and upholstery was often stripped out, so you could get it nice and filthy and just hose it out. Even though these cars rarely had 4WD, they often had good ride heights and clearance and were more than capable of some limited off-roading.
Just look at this list of these sorts of cars and their mainstream siblings from their golden age, in the 60s and 70s. It's like a who's who of iconic, best-selling cars:
• VW Beetle: Thing, Country Buggy (Australia), Myers Manx (aftermarket)
• Austin/Morris Mini: Mini Moke
• Citröen 2CV: Meharí
• Renault 4: Plein Air
• Trabant: Scamp
• Honda TN360/N360: Vamos
• Fiat 500: Jolly
... and I'm sure there's others I'm missing. These were mostly a European phenomenon, though there were some Japanese ones, and you could perhaps argue that the 2WD versions of the International Scout or maybe even the original Jeepster can fit in this category as well.
Fully off-road capable 4WD cars aren't really part of this, as they're too serious and started with a purpose-built off-road chassis. I think this category is more for cars that started as cheap, basic transport and were then turned into do-anything fun cars.
Oddly, many of the cars on that list came about because of military needs for small, rugged, general purpose vehicles. This just goes to show that utility, much like so many other things in live, is a circle, not a line. You'd think the needs of the military would only end up with purposeful, serious cars, but once you go so far to utilitarian, you find yourself right next to fun.
The VW Type 181, which we know as the Thing (or Trekker, or Safari) is a good example of this. It resembles it's pure-military predecessor, the WWII Kübelwagen, and was developed for the West German military as a cheap, durable, multi-use car that could be rapidly developed as they waited for their full-featured military vehicle, the Europa Jeep.
In developing a rugged vehicle for the German military, possibly one of the organizations least associated with the concept of "fun," they managed to also create a car that, say, in bright yellow and full of sun-addled lovely youths in beachwear, is the textbook definition of a particular kind of automotive fun.
This class of car, however they came to be, is pretty much gone today. No manufacturer — at least none that sell in the US — do anything like taking their bread-and-butter base car and selling a stripped-down, fun version. I even proposed the idea to Hyundai, for a cut-down Veloster, and they just looked at me as if I was nuts. I think I probably shouldn't have used the Trabant-based version to sell my idea.