all the cars in my household BMW / MB have 15k intervals... def way too long IMO... once they go out of warranty you run into issues with sensors and other stuff if not more serious problems...
definitely go every 6-7k
example ... m3 got 1200 mile service next service is 16,200 roughly. I will change it at 7-8200 then bmw at 16,200.
my sisters car goes every 6k
mom and dads MB's go every 5k
its cheap insurance... my moms car is out of warranty due to mileage i believe 51k right now. she needs it to make it to 100k+ she drives alot its only a 2010