Game suggestions for a stall in Octoberfest? (racing / driving related)

We're a car-sharing and journey sharing company who are holding a stall in Octoberfest. I'm planning to put up my system there in order to hold a gaming contest, something like NFS (relevant theme). We'll be giving out goodies and (real) free rides to winners / top-scorers.

Can you guys suggest a good driving genre game that's fun, has mini-challenges, etc. I was thinking along the lines of NFS HP2 or Burnout Paradise, but i'm sure there must be something else out there too.

Let me know guys, Cheers!