Use a solvent cleaner to break down the grease and road film (let it sit) then rinse off with very light water pressure. Let it dry completely then use a foaming tire spray and let that sit then wipe off excess. This leaves a nice shine on the rubber and protects it. Also you can use goo gone and elbow grease on the paint expecially on the underside of the hood. The procedure I used when I worked at a detailing shop.
DO NOT USE FORCED AIR!!!! it pushes the water into wireing and other parts and WILL damage them