I just bought a Canon EOS Rebel XTi

I LOVE IT!

I just have a question though... what kind of settings should I use in order
to take awesome rolling shots? I tried but they always come out blurry and not crisp.

 

Hopefully you know how to use the cameras manual settings….if not, try the "sports mode"

Try adjusting the f-stop and use a fast fast shutter speed (1/2000 sec.) Use the cameras blast feature to make fast follow up shots.

Also mount it to a tripod or other stationary device. Although not ideal since the car moves and skakes which transfers to the camera. A gyrostable base is best but expensive.

 

Yeah the faster the shutter speed the less blurry it should be. However the faster the speed the darker the image, so it's gotta be real bright outside unless you got a wicked fast film/detector.