Hmmm didn't know that. I thought the patch was for DLC stuff only. Even more weird that different versions of the game react differently to the patch.
In any case, I've driven the Marussia to 400 miles yesterday so this patch can wait.
All of the sports cars with the exception of the GT-R is quite evenly matched. The Gallardo is a wee bit faster than the R8, but just worse off road, so you should be fine.
I imagine the M3 GTR would be in sports class as well. Would do pretty well if they modeled the handling to be similar to the F1 LM (since they both have lots of downforce from the wing). I imagine the off road stats to be abysmal though
The current M3 in the game is absolutely rubbish. Why they class one of the world's best handling sports cars as muscle is beyond me...