Here are four more pictures. One shows how I trimmed to protector to fit, with the notch for the camera cable. The other three show the protector with bed open, half-open (I drove about 14,000km this winter that way, carrying my iceboat), and closed. I only installed one side for these pictures so you could see the bend clearly. The fit is a bit ugly at the ends, but you only get one chance when trimming to fit.
But there is no free lunch. The protector worked well to keep gravel out of the gap but when I do the final clean-up I generally just sweep the remnants out of the bed with a stiff broom - but the remnants tend to get swept under
the protector. And while the protector is removable, it is not an easy job - although popping one side of the tailgate off its hinge would release the protector's arrow-head-shaped gripper. Still, the protector is better than having the tailgate jam with gravel when 'unprotected' - the tailgate even jams on the way down because the 'user friendly' gate lowering damper slows down the drop enough that the gravel will pack the gap before the gate gets all the way down.
I suppose the ultimate solution is to leave the gap open but remount the bumper with a larger gap to the bodywork so the gravel will fall all the way through - but the bumper is installed on fixed, orthogonally-oriented mounts, so there is no adjustment. Grrrrr. My two earlier trucks, an Isuzu and a Dakota, both had wider bumper to body-work gaps so gravel falling into the tailgate gap just fell right through, instead of being trapped there on the Colorado.
So, I am a little bit disappointed, but don't regret the $39US (or even the $53 for us Canucks).