I got it, but I mainly did it just to race for the Caddy pic. There's nothing really to avoid. It's completely free stuff that doesn't take away from anything else I'm doing in PGR3. Sure the Caddis might not kick copious amounts of butt like they did in Midnight Club 3 Dub(mainly for their special abilities), but it's more free cars.
Needless to say, I'm working out the Nurburgring track, so I have to get used to that, in the first place. Might as well do it with these cars to see if I get a prize. That way I learn a track at the same time.