I have coated quite a few cars with CarPro Cquartz UK, Cquartz dlux, aquapel etc. Although they are all great coatings, I choose to top my coatings with Hydro2. Hydro2 improves the hydrophobic qualities already found in them.
Application is fast. At least once bi-weekly to monthly after a wash I apply Hydro2. While the car is in a cool shaded spot, (PAINT MUST BE COOL ask me how I know) I go around the car panel by panel. I spray the Hydro2 in a Z pattern and hit it with a strong stream of water from my pressure washer. The first time I used Hydro2 it was amazing to see how it cuts through the water to attach to the coating. Finish the wash with a flood coat of water from the hose and there is very little drying to do. I probably do it much more than is required but I have personally found that with enough coatings of Hydro2, even after a harsh Canadian winter and using touchless car washes with their overly strong chemicals, the Hydro2 is just starting to wear off come spring.
Hydro2 is also great to use on an uncoated car. My brother received his brand new WRX in November. Being too cold to do a proper paint correction and coating, I chose to do a decontamination to rid it of all the rail dust and adhesives from the factory and applied a coat of Hydro2 on the vehicle for the winter. I looked at the car a week ago and it is still beading nicely!
Highly recommend this product from CarPro and Eshine!