Yeah, Road Rash is doable. Top Gear 2, though? As I said, compare the SNES and Genesis versions of that game... the Genesis version suffers badly in comparison to the SNES version, and do people think that the TG16 (or CD) could have beaten the Genesis port of the game?
But Road Rash... that's probably much more doable at a level close to where it is on Genesis, sure. I'd accept slightly worse graphics if they could make the framerate not terrible, too... you know, like Outrun, where on Genesis it looks better in screenshots, but on TG16 it plays better because it's not horribly choppy.