There are many ways for a car cleaning.
first of all if you have the time to make a really deep cleaning try the following:
1- take out all electric stuff(motor,esc,servo)
2- re-assemble the car(all parts dont leave a screw in the car)
3- take out the ball bearings and the shocks.http://www.balakracing.com/cleanballbearings.htm
this is a link that shows you how to clean your bearing.
4-give your car a bath!
, with an old toothbrush and a cleaning detergent(the one used in the kitchen) put all the plastic parts in the water and then just brush them with the toothbrush and the detergent. after you finish the cleaning wash it last time with water to take all the soap out of the car.
5- clean the parts from extra water with a hair dryer or a high pressure air.
6- reassemble the car and clean the shocks from out side, if you want to clean the shocks take out the shock oil and clean it the same way you did with the kit, and then re-oil them and fix them.
put all the parts back(motor, servo, etc..).
Remember to not use any thing that have oily stuff because all dirt will stick to it.