I know I'm going to catch hell for this but, I go to the car wash and use the high pressure to get the bottom of the car, wheel wells and motor clean. My engine isn't dirty, just dusty so it doesn't take much. I only do this once or twice a year. Just make sure you don't directly spray any electrical componets and keep the car running. Just in case. After it dries, I spray everything down with Almost Magic and let it sit overnight then wipe it down. Keeps everything looking new. I do this to all 3 of our cars even though they didn't start out as clean as the GN. If yours is greasy, try the degreaser/tire cleaner at the wash. I've had very good luck getting even the dirtiest engines clean. Good Luck