A couple of times, I have used vehicle washing stations with raised sidewalk platforms or wheeled stepladders to reach the top of my van. These facilities had pressure washers for use. Though my recollections are that I used the foaming brush after a wash with the pressure rinse while taking care around the decals.

A home, where I do the majority of washing, I have a tall step ladder, vehicle wash detergent, a soft vehicle cleaning brush with a long handle, usually a simple garden hose spray nozzle and sometimes my domestic water pressure blaster avoiding the decals or edges of added paint.