I think it might wear off but I have spent the last few afternoons (4) polishing my 55 plate 325i SE. Its a Arctis Blue Metallic one.
Basically started with Roof, Boot & Bonnet Then did front wings & front doors, Rear quarter panels & rear doors. Today finished with front & rear bumpers & sills.
All done with "Hard Turtle Wax Metallic" green coloured wax from a tin that must be 8 years old. Can't remember the last time I used Hard Wax !
I suspect it is some sort of new vehicle Virus I have caught.
Reason for changing from Mercedes was really due to wanting a smaller vehicle as the smaller C Class models just seems to get bigger with every new version.