Hmm. I have the following:
Mugen Super Athelete
Mugen MBX-4 XR
Mugen MBX5
Mugen MBX6
Mugen MBX5T
Mugen MBX6T
I don't think any of these are bent in the rear??
1. It's called kickup
2. I bet is has to do with not stabbing the chassis into the ground when braking or when landing on a jump. helps to keep the lawn dart effect from happening when driving normally. Allows you to skim over things and not get hung up.
Hmm. Sounds pretty good huh??