A Zuma is an ok boat, by why not get a laser? Then you can race.
If your serious about a small open transom dinghy, also check out the Xcite.
It's plastic so it will stand up to abuse a little better (won't shatter
when it falls off the car).

I've sailed both. Though they both weigh about the same, it's easier to get the
Zuma off a roof when you're alone. The Zuma is less of a performer, but was
easier to get the hang of and was more stable. I had more fun on the laser, but
the Zuma seemed more rugged with it's toy-plastic hull.

RB