RepairPal Certified shops can diagnose and repair your 2006 BMW 750i. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.
Get it inspected as soon as possible it could be several things but most likely to be a brake pad "gone metal to metal" which could compromise the operation of the brakes or it could be a bad wheel bearing.
Agree with patrick, I am leaning toward the wheel bearing.