I like the idea of a “good” car with a “bad” engine (in terms of power, maintenance, parts, reliability) because it could be made into a “great” car for the small price of swapping in a better engine. Like how I could be an awesome all-around student of automotive design if I could trade brains with Ian Callum or Adrian Newey.

Some cars that come to mind immediately include the Nissan 300ZX, due to poor availability of parts for the VG-series V6 engine. It’s a great-looking car, but a difficult companion if daily driving is your goal:

Also any car with a rotary engine could be made less maintenance-intensive with a different powerplant swapped in. The FD RX-7 is another great-looking and high-performing car, just a heart transplant away from being perfect...*

*Not to say rotaries can’t be perfect too...

I’ve only described two-door Japanese coupes from the ‘90s but I’m sure there’s more variety out there. What other cars’ most problematic features are their engines?