I suppose it all depends on how often you roll your windows up and down and climate.
Or
Luck!
I wouldn't have said that if I were you! Better go knock on some wood!

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E36 M3 Schwartz on Schwartz
E36 328i hellrot(ed) clear coat
E70 X5M (12) its black on black too!
E53 X5 (06) 4.4 sport Imola
P38 Range Rover 4.6