The idea with the crayon I find quite good, but he is not appreciably different from a crayon and can be at, for example. normal-sized rockfalls insert only very limited in the place.
The small stone chips of max. 0.5mm are then repaired after laborious treatment to nächstgen car wash.
Regarding the polish / wax: is classified as wax. Because
constitutes only minimal and very fine abrasive grains.
Conclusion: a good idea, not implementation