If you want to strip your painted surfaces of all wax, grease and oils give Palmolive dish soap a try.

If you need to remove tar try finger nail polish remover (Naptha?) and a Q-tip. Just take your time and work one small spot at a time.

Than if you still find a spot or two of dirt/hase you can't live with give Mothers clay bar a try, its not as agressive as some you can buy at a paint supply store, but safe enough for someone who has never done it before.

Follow that with a good glaze, polish and than wax!

Just my .02 cents worth, your millage may vary