I use a low profile floor jack when I do my own oil changes. The jack I use has a deep "bowl" in teh part that contacts the car body. So I went out and bought a regular old "hockey puck" from a sporting store. Nothing fancy. Just a rubber hockey puck.
I put the hockey in my jack's "bowl" and then lift the front sides of the car at those plastic rectangle pads. I normally just lift my car from the driver's side pad just behind the driver's front wheel. Once the car is high enough in the air... I put some jack stands under the car.
To raise the rear of the car... (like to change the diff oil) I raised the car from the diff housing. I know BMW says not to do that(!) but I too did not see any other way to raise the car - safely. I used a block of wood between my jack pad and diff housing (to spread the lifting load). Having some assorted wood pieces around ones garage helps in these times of need!
I suppose you could also lift the car from the metal subframe "knobs" The big black steel cradle where the rear suspension bolts up too. But I was too afraid my jack would slip off at those points.