Cracked Rocker Panels
The cracked rocker panel problem is very common. On another forum, 48% of all Challenger owners polled have experienced this. Some of the suspected causes are:
1. Cheap plastics.
2. Body flex.
3. Cold weather.
4. 1/4" too short.
5. Garage car lifts.
If you go to the dealer, they should cover the replacement under your warranty. To be safe, print out the many complaints on the forums and take them with you. You should complain to customer service to document your problem. There is a writing campaign that is starting to make Chrysler produce better engineered replacements.
I have a cracked passenger side rocker and intend to get it replaced in the Spring.