Correct, no bed covers on rental trucks as they're an (expensive) after market option. The only truck with a trunk is the Ridgeline and I've only seen 1 of them in a rental fleet (Avis, and I've had the pleasure of driving it 3x). I'd definitely go for an SUV unless you want to risk getting your bags drenched, plus moving them in/out of the truck every stop so they're not exposed in the bed.