I've never seen the show, but was this one of those jackass stunts or something? :)

You've missed the obvious. You should have been using white grapes. I'm pretty sure that's what professional grape tossers us.

dude - use a fucking WATERMELON. You'll be able to catch that one when it lands on your face. And thank god the roads you're making unsafe are out in Cleveland. Hey, you know the song "Funky Poodle," by the Wild Horses, you party animal?

Oh, the things we do to amuse ourselves....

I read this after I read your dark matter post and couldn't help but notice the connection: you, sir, are a closet science geek. Experimenting with grapes in a car is probably somewhat safer than your "experiencements" with electricity, maybe; can't you find something to play with that has a minimal risk of killing you- or an innocent bystand/driver- off?

Inquiring minds, ya know...

If we see white VW Beetle with a black "The Who" sticker on the rear bumper and purple grape stains we'll know it's you.