...do "retro" or "classic" versions of old cars with new mechanicals, etc.?

What I'm thinking about is, for example, something like the 1964 Ford Mustang.

Most everyone loves the look of that car. I understand it doesn't have all the required mechanicals of the modern era, but why couldn't Ford design a new mustang that looks more or less just like it on the outside? Wouldn't that sell as big, if not bigger, than the modern designs?

The closet to the big companies doing something like this would be the Ford Thunderbird remake about 10 years (which didn't look all that much like the 1950s version) or the new Beetles. You might also throw the Mini Cooper into the mix.

And not just Ford. Why doesn't GM bring back an early 60s era 'Vette design or a mid-70s Camaro look? Or a Cadillac with those big 'effin batmobile style fins?

Is it engineering? A refusal to admit the old stuff sometimes just looks better?

Any thoughts?