or just make sure you park truck in shade and wait. if i plan to wash my truck it sits in the shade all day until it gets closer to nightime then gets washed in the shade. i can take my time the wate doesnt dry and then I dry the truck with a 100 percent cotton bath towel with teh edges cut off to prevent swirls. there is no need to buy special filters and such if you just use a little common sense and dry the car. water doesn't leave spots just because it's hard. IF YOU LET IT DRY ON THE CAR almost any water will spot. to be honest once the hood is dry ittakes maybe 20 minutes to dry the entire truck. that's not much time at all. I allot almost 4 hrs of time total to wash my truck dry and wash and dry wheels. five hrs if i do the interior and door jams.