the brushes and the soap are the main things. i wouldn't worry about dragging it to the car wash, just scrub the crap out of it. and don't use the green scrubby pads, they leave pieces all over the place. try and do it at the hottest part of the day, blow everything out with air if you have it available. a heat gun is good too. anything to get it dried and soaked in oil when you're done
