I use the Indy race for XP and money. I just did the Dream Car Challenge with my race modded ZR-1. Did take second in the fourth race by .073 seconds, (slid off the track three times and the Jag cuaght me). But beat the Jag by 43 seconds the last I saw I was ahead--before anyone could cross the line it closed out that screen at the finish.
I was thinking of starting a thread of favorite races--have not seen one yet. That 24H Nurburgring course in the rain against that competition...loved it. Favorite race so far. Of course, trying to nurse a 860 HP Vette around the course in the rain with a DS3 controller was a bit of a challenge!