Bmw e61 520d 2006

[kofo]

Please assist if you have any idea about below issue with my BMW

Vehicle: BMW 5 series E61 2006

Mileage: 310,000 KM

Problem: rear wheels stuck (jammed)

Time: winter (below freezing temp)

Details:

Something is frozen or stuck in the rear wheels happens in 2 cases:

1- after I wash the car while temp is below freezing drop to freezing point or below and park it outdoor.

2- During rain while temp is +1 or +2 and once temp drops till zero or minus.

car simply doesn't move just few cm forward or backwards but no more and i always needed to press accelerator so hardly until wheels got released causing huge bang sound.

sometimes both wheels don't get released at same time but it happens individually which makes it much harder to release the other wheels as the free wheel keep spinning.

After all this effort and both wheels are released this issue doesn't happen again even if I drove the car 100 times and temp is -20

but only way it comes again when one of above 2 occasions happen.

i have replaced the whole rear braking system (disks , pads & handbrake system) and simply nothing has changed even my car garage admitted that he can't fix the issue because it's so mystery for him.

Please if anyone has seen or tested the same issue before to help me what is this exactly.