Since you experienced the same thing on your other twice on your other 5 (after 2 years and now, with your mom's new tires, this sounds kinda weird. Are these all different brands of tires?btw, when did you first notice the problem on your E60?
I'd be curious what would happen if you put your mom's tires on your car? or if you put the spare on? I don't understand why they can't be rotated. An easy way for the dealer to test your car is to put on a whole set of new tires/rims from another E60 and test drive it a few miles. Or they can change out one tire at a time and test drive it each time until all the tires/rims have been replaced to determine if it's not all the tires making the noise.
Either the problem is there or it isn't.
What manuf/model/size are they? Are all the tires making the noise?
I have 18" Dunlap runflats on mine (2800 miles). The only time one of them made noise is when one of them went flat,otherwise, they are fine to drive with.
Since this is happening to everyone, it sounds like its the tire.
What model number of rims do you have.
What concerns me is that it is happening to your other 5 also.
2004 E60 530is, Delivered 12/12/03, TiSilver/LGrey, PP, SP,PS, PDC, ACC, FRS, Step, Xenons, clear bra, body colored rear inserts. (Retired, 1983 henna red 320is)
2004 Corvette Z06 Commemorative Edition