Its probably a combination of things. Some Bimmer drivers are "stuck up" to say the least. They are unwilling to use Meguiars car wax. It has to be P21. Wont use Castrol Syntec oil. Has to be Mobil1. So many aftermarket companies play on this IMO. Additionally, Bimmers are well built compared to the US built cars such as the Mustang and the audience is completely different.