I've searched the archives but can't seem to find an answer: will spraying in a liner help the super-thin bed walls & top of rails be more resistant to dents? How about cracking in the corners?

Has GM done anything about the cracking bed problems since last year? (doubt it, but had to ask)

I already have a sprayed liner, and an over-ther-rail tool box, so I guess it's a little late to add the reinforcing brackets...