2-3 sprays is about right. I use the finer mist setting (not the spray stream) and it only takes about 2 squirts per panel to ensure complete coverage. Then, just wipe around and off. Easy as pie. Even if you use too much, it should still wipe away cleanly, unless it is humid or the surface is too hot.
The way I do it is...I use 2 towels...1 to wipe it on with and one to wipe off....I spray the wipe on towel once or twice..just to get the towel damp....then I do 1 spray per panel..wipe in with the damp towel....wipe off with the dry towel...the wipe on towel will get damper as you go and spread the product around using less ...so this works fine doing 1 spray per panel and 2 for hood and roof..
i spray onto the panel and spread it around lightly with a mf square applicator, and then buff away excess with a mf towel. this method has worked for me with no probs...