A few months ago, one of the pneumatic cylinders on my suspension failed - the car's rear collapsed onto the rear wheels, I got an error message about driving very slowly, or getting towed, and etc.
Got the cylinder replaced, and happily forgot all about it.
A couple of weeks ago, I step out of the house, and I see my E70 slumped over on one side (not the side that was fixed). Starting and running the car does nothing - the thing won't inflate and level, yet there are no error messages anywhere.
I didn't have the time to deal with this, so I just drove our E71 for the next 2 weeks. As I figured its time to take the E70 in for repairs, and being too cheap to pay for a tow truck (the mechanic is close buy), I started driving it, and 500 yards later, it suddenly levels out. Been driving it since, with no issues (touch wood).