The drop-in plastic liners are very slick, and if you haul a load of lumber to build an office in your basement, the lumber will slide out when you take off from a slight uphill (insert red faced redneck here). :bigsmiley20: Last time I borrowed my father-in-law's truck.
Had my truck sprayed the same week I got it and have never had a problem. I would not even consider a drop-in liner for one of my vehicles.