It is fun, except that the AI is a fucking cheating bastard.
Not all that unexpected in an arcade racer, but I can't tell you how many times I've had a decent lead on first and due to a mixture of blatant rubberbanding and weapons of mass convenience, I wound up getting demolished five seconds from the finish line. Argh.
Oh, and quickly, Steam crashed and when I click the icon it does nothing, how exactly can I get steam back up without restarting (my internet just seemed to unfuck itself, and I want my Witcher).
If you're referring to getting Steam back up without restarting Steam, I doubt you'll be able to do that.
You might as well just end the process and restart it. If you were downloading anything it should continue where it left off.