If you don't have a power washer this is almost as good.
Costco sells the Bon-Aire Ultimate Water Blaster UWB-1HD for $15. Home Depot & Lowes sell them for $20.
The tool extends from 3 1/2 ft. to 6 ft. The end pivots full 360 degree rotation. Ball valve shut off at base. Works great to rinse mud or salt off underside, engine and wheel wells.I use it to wash my whole truck and car. Comes with fan & jet nozzles.