Anybody have any info on whether or not the black bed rail covers on a 2010 tacoma should or should not be left on with a flippac? I removed them in anticipation of having my flippac installed. The installer told me over the phone today that they should remain because thats how FRP measures when they build the unit. I'm suspect because with the covers on the sides of the bed are at least 3/8" taller than the front and the tailgate. Thoughts, experiemce???