Ah sorry, I misunderstood

You dont need to hit cars with G3 to make a difference. Pre wax cleansers cam make a massive difference to cars appearances such as Zymol HD Cleanse, Swissvax CF, Dodo Juice do 2 lime prime and lime prime lite. I favour the dodo based on cost and my consumption!
Lime Prime on older less pristine cars as it contains microabrasives and will improve the paint no end
Lime prime lite has no abrasives and I use on good condition paint, and follow these by waxing.
As a start you can try washing and claying a car, then cover with something like Autosmart Platinum.
You can wash, clay, cleanse then use AS Platinum before you delve into expensive waxes and sealents....there is a whole world out there!
The basic detail procedure though is wash, clay, cleanse, and seal be it a wax or sealent. You will read people say they have a "100 step process" but it boils down to the basics above

Tim