Painting over wax will result in the paint coming off as the wax comes off.
You could do a 50/50 mix of IPA and water on a cloth and apply some elbow grease to the over waxed parts and then thoroughly wash the truck when finished. You could also get a DA buffer and a water only damp pad to remove the wax. Or you could just wait it out as the summer time will soften that wax right up and you could wash it off over time.
Sorry for the dumb question but what is IPA? I'm guessing you aren't talking about beer.