My detailer says this is an issue with all OEM paint jobs.
The best solution is to apply a sacrificial coating to protect the paint. A solid wax job will help, but even better is something like Opticoat or Wolf's Hard Body.
2013 ///M5 Individual
Monte Carlo Blue, Platinum Full Individual Merino, Platinum Alcantara, Piano Black, Exec Pkg, Drivers assistance pkg, Bang and Olufsen, 20" wheels
Eisenmann Sport Exhaust, Bel STiR+, Laser Interceptor QUAD HP, Zaon MRX