As said by many, I also have an old car, with very faded cracking heat damaged color, rust everywhere, never a problem. Note if you change the color then you have 7 days, to register that in the book. Also one time at the transport office which I now NEVER use, took the old NV but I'd taken off, the carboy type cover off the back, they insisted even that had to be changed in the book before they would pass it, that is so crazy as I tried to point out to them, sometimes I want it on. . so in theory every time I'd want to use i, then I'd have to change it again! That ain't going to happen ever. Hoping the cops will never pick up on it.