It's not the application technique, but the material being applied.
Chrome plating is a process where actual molecules of chrome metal are attracted to a surface using electrical current. It covers the surface of the parts with a layer of real metal. Of course metal is very hard, and will be difficult to scratch.
The strength of paint will be limited to the materials it's made out of. For instance, brush on house-paint is very weak because it's made of latex. Typical spray on paints for cars use very strong binders to create a glossy shell of a surface, but they are still limited to the strength of a sturdy plastic.
Since you mentioned "electrostatic", Powder Coating is a "painting" process that uses just that. A fine, dry powder is applied to the metal and it clings in place using an electric charge. The piece is then baked at high temperature that causes the powder to melt forming a solid glossy surface. Powder coating is common on bicycles, and gives a thick, strong surface, but it's not as strong as that metal razor blade!
The strongest "paint" I can think of is glaze that is used on ceramics. The glaze is brushed on and then fired at very high temperatures that turn the glaze into a shiny, glass finish. I wonder if there is a way to glaze a car, but I suspect it would be too heavy and too prone to cracking.