I use 50/50 simple green and water in a spray bottle. Spray it on, let it sit for a few minutes and then hit it with a bargain bin cheap-o paint brush to try to knock off as much crud as you can. I then hit it with compressed air. I repeat wash as needed. For real cruddy areas I use denatured alcohol. To rinse I use 50/50 Armor-All and water in a spray bottle...again hit with compressed air. Whenever you do this though do pay very special attention to your electronics and do not get them wet. Set in the sun to dry.....hope this helps.
******If you use carb cleaner or brake cleaner be very careful as it will stip paint and can also damage some plastics and make you more prone to breakage.******