So far, I'm unimpressed with the Gtechniq G5 Water Repellant Coating. So I decided to not apply it to the windshield. I then bought the G1 ClearVision Smart Glass product. It comes with G2 Residue Remover. That usually gives me pause, when a product requires another special product to remove its residue. But I'm willing to give it a try. There's got to be something good that lasts longer than Rain-X. It's not as though it rains much where I live. But the product isn't expensive, and I'd rather test it on a factory-new windshield.
The application instructions and video seemed easy enough. They key parts being: (a) wait 5 minutes & no more after the 1st and 2nd coats on the windshield, (b) wait 15 minutes & no more after the 3rd coat.
Before applying the G1/G2, I used the G4 Nanotech Glass Polish. G4 is easy to apply. The trick to buffing it off is to first wipe it gently with a damp cloth, then buff off the remainder.
I followed the instructions and put 3 coats of G1 on the windshield in the sequence described above.
G2 removed the residue as described. It evaporates fast after applying to the glass and it smells like it might be IPA. The trick is to apply G2 to very small areas at a time. For me, this was about 1/9th of the windshield. If you wait too long and G2 evaporates, then it's hard to buff off the residue. If you apply G2 to a small area then, before it evaporates, it's super easy to gently wipe off the residue.
I also cleaned the wiper blades (as instructed by Gtechniq), although it's a new car so that was easy.
My first drive after treating the windshield showed only a few spots where I needed to buff a bit more. I hope it lasts as long as advertised (30,000 miles).