If you're going to use a clay bar, I would suggest you use Dawn dish soap to wash the car first. Since Dawn has a high alkalyne content it will remove the wax build-up on the car.
Once washed you can then mix a small amount of Dawn with water and use that in your spray bottle to help lube the surface while using the clay bar, also keep a hose handy to rinse off each section as you complete it. Once the whole car has been clayed, wash it once more with Dawn. Next dry the car with either a chamois or water blade and then use the quick detailer on it. Next is to apply your favourite wax or polymer.
Be sure to fold or flip the clay bar as 'stuff' accumulates on it.
This should take you a few hours...enjoy!!!!