Actually, there are some areas in GTA3 that was ommited from SA.
A step backwards if you ask me. It's those little things like water puddles on the roads which added to the atmosphere. Also, the cars get damaged better, in VC and SA, the fenders don't get bent like they are constructed from super alloy or something.
I'd like to see them back and enhanced in IV. And no omissions from later versions too.