I have bottomed out twice. Neither was on Speedbumps. So far, all the speedbumps I crossed have been lower than my clearance (and I go over quite a few).

The two time I have rubbed have been due to very steep hills:

1) Radio Sack (Scatterfield & Mounds Rd in Anderson, IN... beware) up on a hill with a very steep entrance. I rubbed as soon as I started up the entrance. Luckily, I had the radio down and heard it right away. Backed off and came in at an exagerated angle, no problem.

2) My dad's brand new driveway (first weekend I had the car). As soon as the front tires hit the level part of the drive the middle of the car hit (too sharp an angle on the transition). I was soo PO'ed I backed off and drove through the nice wet lawn, and cursed at my parents in greeting. :evil: Ended up convincing him to tear up the end and re-pave the incline at a lower/longer angle that weekend.

Speedbumps are all different. But, from chrysler's website:
"Ground Clearance (at curb weight) [in]=4.9"

So, I'm certain it won't take long to find one 5 inches or so that does rub.