Well, I'm working on it. Here's a little Civic-sized 2+2 coupe using some of those pieces that are in LDD. Again, it shows what's possible. Please pardon the mixed colors.

I'm of two minds about this curvaceousness. On one hand, I like this result. I'm starting to appreciate what other AFOLs go through. I thought I was already looking at my work in the cold light of day, but yeah, no wow factor.
On the other hand, I like my squarish cars just fine. My only goal was to fit five minifigs in the box. *sigh*
I've realized, LEGO has done the curvaceous thing too with
the Speed Racer sets. But my primary context was the
dinky cars from the 90s. Those things, like my boxy cars, only vaguely resemble their real-life counterparts, and yet they are iconic sources of nostalgia. In fact I think LEGO sets have a certain charm when they
look unrealistic. You know, it's campy.
But of course, if that was enough for me, I wouldn't be designing five-seater cars.
Hmm, that's more complicated than I thought it was.