After 3 million miles in pickups I've had both liners and spray on. I carried a lot of farm equipment that I did'nt want sliding around. My favorite drop in liner was a skid resistant pendaliner. The Ford spray in liner is too slick for me, so I look for a spray liner that stays a little...
After more than 30 tries over a 3 week time frame the procedure worked. Don't ask me why it worked. I had tried at least 10 times this evening and then it just worked. If I added up all the time I spent researching and seconding guessing everything, it would have been better to have a dealer...