I was testing a few things and tested out the Yugo - i noticed two issues:

It flips easier than any other vehicle i've ever driven in Project Zomboid. Seriously, any corner will lift a rear wheel off the ground. I'd definitely recommend tweaking whatever makes it so top heavy!

And it is far slower than the Yugo-like cars i've driven IRL (such as the Fiat Uno here in my country). It's not meant to be super fast, but seriously, the real life Yugo (the 1.3L sold in the US) is even faster than the 1.0L Unos i'm used to, and they're not even nearly as slow as the Yugo i see in game! I'd recommend upping the power to be more in line with the other simpler economy cars (that is, more in line with the Jalapeño and Dart).