How do you clean or replace the clear plastic film on the leading edge of the rear fenders?

 

They used to be a stock item at dealers. Or, you could go to you local window tint shop and ask them. Or you might find some of the plastic ones from 2007 models, maybe a PM to hellshotrod.
Once again we must ask: why does one side cost more than the other?

 

are the hard rubber ones needed on a ss ?

 

They were put on because they are cheaper than running boards. If you got running boards you don't need the rock protection.

The story goes: 2006 model did not have any protection, when people started complaining some dealers gave them running boards. Then in 2007 models they put a plastic stick on protector on cars without running boards. Then 2008 onward they put the film protectors on cars without running boards.