i wouldn't use that foaming degreaser on you car...too much aluminum for it to screw up and depending on the color it will fade the paint on the firewall too.

Differant areas will need to be cleaned differantly...the block/head and transmission can be sprayed with brake cleaner, that will break up any grease or oil gunk that has built up and clean it at the same time...the firewall, fenders, and everything attached to it should be sprayed with a diluted degreaser like simple green and try to wipe it with a sponge or rag. Mix the degreaser with hot water and you can rinse it with a water hose if you keep the pressure low and don't spray...just left the water run out like waterfall and down everthing you wiped. The radiator and hoses can be cleaned the same way and then you can wipe all the plastic and rubber down with armoral and/or tire shine...