Really high end cars and people with big cheque books people often get a full paint correction, 3m or similar self healing protection and then apply ceramic coating over that... costs about 5k but looks like you have 10 coats of clear on it its pretty cool.
My brother did a full wrap on one of his cars, was around 5g. I just want the clear film, and was thinking 5g ish.
I have bright green paint, so the rock chips show.