I use about 1.5 oz. of Dawn to 3 gallons of water. I usually slip in a half ounce of WG auto bathe as well to soften the water. The Dawn will remove most grim and grease, and better than any dedicated carwash I have used, but Dawn is only good for the initial detail before claying and a paint cleanser or cleaner wax/sealant. For adhesion purposes, IME a paint cleanser or cleaner wax/sealant (I use KAIO) is a crucial step after claying to help wax/sealants adhere to the paint better.
I have never used the chemical guys wash, so I cannot make any comparison. But many members here recommend it as an initial wash.
This is the process I use for the paint in an initial detail::autowash:
1. Wash with Dawn, and then dry.
2. Clay the paint from top down, wiping excess clay lube (I use ONR) from the paint to help against spotting.
3. Use Klasse all it one. This is a cleaner sealant, and it shines up the paint a little bit. You have to work the KAIO into to paint a bit to remove environmental contaminates and leftover wax/sealant that was too strong for the Dawn to remove.
4. Sealant.
5. Carnauba if desired after the sealant has cured.
Now I would never risk washing a vehicle with Dawn after applying any wax; sealant or not. This is where good dedicated carwashes are best. When your vehicle’s paint has proper protection (sealant/wax), a regular wash with a good boutique wash (like WG auto bathe; my personal favorite. Others are XMT, Pinnacle, DP, etc.) has immeasurable advantages over a Dawn wash. The boutique carwashes have great lubricants that help prevent marring and make washing a well protected car much easier and more rewarding. When I have used these washes on a waxed car, bugs seem to wash off so much easier (which may actually be a combination of the wax and the wash). I have even noticed more “pop” from a paint job after washing with them. The boutique washed even claim to recondition the existing wax on the vehicle, which may very well be the reason the paint has some extra “pop” after use. In theory, regular washing should help waxes/sealant last longer.:dblthumb2:
Of course, this is all my opinion and experience. Im the MAN