That would be an expensive undertaking. Clear coat is the second stage of a two-stage paint system, the first being the base coat (color). First the surface (all of the car) would have to be properly prepped and for best results all the trim removed. To do a good job a competent body shop would not be cheap. Unless you blow the car apart like street rodders do (remove everything, including doors, trunk, hood, windows, etc.) the new clear coat will not look as good as the new factory paint. For example, a new car is painted with nothing on it (windows, weather stripping, etc.) so all areas, including doorjambs get done. On a repaint there is no way to do that, so masking and blending would have to be done.
Then depending on the thickness of the new clear coat, and the color of your car, the paint may not look as crisp or bright, especially if a metallic is involved.
Actually I’d never even consider doing that to a new car. The factory paint (clear coat) should be more than adequate and with proper care last the life of the car.
If there are areas you’re concerned about getting rock chips, etc., you’re better off looking into a bra for protection.