Each time I leave the car outside I put a wheel strip on the car. It is a good one and somewhat unique for the car. After my E70 was stolen, I took advice from a friend and got one for my E71, they tried to steal the car (right after it came back from the service
and that's the only thing they could not take off, every compartment was opened). Anyways, an sure it is not perfect, but it is better than having nothing. What it sure is IT IS IMPRACTICAL! It does not help that after I close the door, the steering wheel changes position so I have to open the door (unlock) to adjust the setting again (otherwise it might damage the steering wheel). On E71 as soon as you adjust it once it would go away, here I have to play with until it sets itself. I tried ticking off the option of automatic seat adjustment (not sure what's it called), but the steering wheel keeps moving in auto mode.
I must say that this is annoying for me, but if I would not have to put the wheel strap on, I must say that it would be a nice touch.