e46 on jack stand, steptronic in N, rear wheels turn

I've got a question since I've had to analysis what my problem was, which was a whirling sound heard in the cabin, seem to come from outside rear, from driver's point of view. I compressed the brake piston on each rear caliper, checked the sliding pins, and bleeded the brakes.

forgot to check e-brake, I suspect it's the ebrake. Will open up when it gets a little warmer, not as loud now.

When I had the car on jack stands, I put the steptronic auto in neutral and released the brakes, the rear wheels are driving. Is this normal?

Mind you I only had the rear up on stands, the front wheels on the ground.

If it's not normal, can anyone show where the tranny cable is to adjust.
I'm still new to BMWs, but not new to fixing cars. As my 04 325 is drive by wire, I'm sure of it. In the past I could adjust the throttle cable and tranny cable (they are the same) on honda integra automatics. I suspect the tranny cable is too tight, which means it keeps the tranny always in gear.
Can someone please tell me where the tranny cable is if it exists on the bmw, or even better post a diagram/picture? I've search the net and on this site for a few hours.

How much were they turning? Like, full steam ahead?

not full steam ahead, I'd say 5-10 kph??? They are not still. it spins at a low rate of course.

I'm asking if you put steptronic in neutral, are the wheels suppose to turn.