camping world has the track & curtain "hooks" that slide in the track.
for camping in roadside rest areas we find the curtains to be adequate but nothing more, cause they let too much light in & don't do anything to block the heat.
I custom cut some sun / heat blocking window shades out of a roll of FOIL backed double bubble insulation (again camping world has huge rolls of this stuff).
when we're in campgrounds/racetracks or curb side at my mother-in-laws for even 1 night i put the dbl bubble shades in the windshield, doors & pilot window (bottom of the door)....talk about making it DARK (and blocking almost ALL the heat)....its cheap, they work & they the custom fit is perfect !