Did both of the rear struts and springs a few years ago, but find the right side one has broken right at the top and will need doing for this years MOT test. As usual with 5 Series models when the spring snaps at the top or bottom, there was no tell-tale clunking or change in driving characteristics, so who knows how long it's been like that. At least it is not a big job.
*GUIDE: F10 Rear Shock / Spring Replacement*
*GUIDE: F10/F11 Front Shock / Spring Replacement*
The rear struts were replaced several years ago from a car with 80k miles. Their combined run in both cars has still added up to less than the mileage on the original ones!