zyx5432:
After talking with guys who work/worked at an auto assembly plant, I arrived at the same conclusion that others have stated here.
What I mean to say is the process of painting a car at the factory is totally different than at a body/collision shop and even the paint is different. As such, the paint has to be "fully cured" before they can assemble the vehicle and surely by the time it arrives to the lot.
So wash and wax away.
Re-finishing, what the body/collision shops do, have different requirements for when you can or cannot wash and wax but the process used is different and so is the paint.