ETHYL

What have you used to remove the old wax from the paint. I have heard that Dawn soap may remove wax, however is another method available. The directions on the poly wax bottle states that the old wax should be removed before applying to insure a long life for the poly wax. Otherwise, when the old wax breaks down under the poly wax coating, it's coating life is shortened.

yamabob

To some degree I think the dish soap is more myth. I too am guilty as I will do a Dawn pre-wash with a cap full of APC . There are several products on the market that you can choose from. You will more than likely see them as paint cleanser's. I have many ,many times used CarPro Eraser. A nice wash-clay and polish should remove old as well-especially if a coating previously applied -polishing is the way to remove.
Go to autogeek and check them out. What seems to be a well thought out and budget friendly line is their McKee 37.

0Killrwheels@Autogeek

There are several choices, often the easiest is polishing which abrasively removes any old wax. If not you can consider a chemical cleaner or solvent based paint cleaner as desired.

For nice paint, I often suggest using a cleaning lotion to prep, one like Pinnacle Paintwork Cleanser or P21S:

http://www.autogeek.net/wax-remover.html

cmonkey713

I have found that Wolfgang Paintwork Polish Enhancer works pretty well after a water/ alcohol mix wipe down. it works great with a Lake Country yellow finishing pad.

SouthBaySurfer

I am not a fan of using Dawn on my car. As a detergent, it does nothing good for plastic and rubber trim, and over time, I think it will dry those items out.

0Killrwheels@Autogeek

I too prefer to use a dedicated paint cleaner and leave dishwashing liquids in the home. There is no proof that Dawn removes all of a wax, it does remove the oils and beading, but may not even dent a fully cured sealant.