I have coated 4 cars, all with gtechniq or 22ple. You must must must get all the wax off the car.
Clay bar the car first, then polish if needed, then use an ipa wipe down or a dedicated prep solution with a da polisher. Gimme a day or so and I?ll post a pic of everything you need. Detailing is one of my hobbies. Reputable shops charge $700 up, but a lot of that is paint correction. With a new paint job a single stage polish may lower that price. On a new car I charge 225 plus the price of the product. I coated my current car 13 months ago and it beads up better than if it was waxed yesterday. The shine cannot be duplicated with wax or sealants.