I was a paint rep for a Carquest store about 10 yrs ago and I remember our local Chevy stealership used this bed liner quite often. It seemed to be ok but I distinctly remember when I first took the job there was an issue with the Sem tintible bed liner. Turns out a customer bought a new Chevy truck and had them spray the liner in. It was a tan (sandstone) color and they did the appropriate tint to match the body. They used a PPG basecoat to tint and then the unthinkable happened.
The bed liner never activated! It remained soft and gooey even after 2 weeks sitting in the sun. So they call us up and of course I had to check it out. After finally accepting the fact it wasn't going to harden, I was told to remove the coating any way possible.
I used putty knives, razor blades, wire wheels, lacquer thinner, 36gr. feather pads, anything I could think of. It was a terrible way to start a new job. I think I was at it for about 2 days and finally ended up just spraying over the remainder bed liner that couldn't be removed.
I think that was just a fluke deal but you never forget something like that. I would have to say watch dates of activators and mix well!