I havent done those yet, well the All Stars I have but I got my ass kicked. I used the trusty Veyron for those. My ZR1 is fully modded and makes about 8-fitty, I know someone else said the Vipers make over 1000HP, not sure how usable it is, my ZR1 burns tires pretty good. I love launching it in 2nd gear and laying down a huge patch during the Special Stage Route 7 tunnel dragz. It makes the younginz go super hyphy.
The Audi Quattro Pikes Peak SUV is fun to slide too.