Are they offset sizes? I have 19/9 front & 19/10 rear

If they are different widths it is possible one or more are swapped & contacting?

I`m thinking parking brake seized or calipars seized thats the only logical answer I can give you. someone else might think of something else though. its only changing wheels what possibly could go wrong.

Jack up both rears at the same time and attempt to turn one of the wheels by hand. If they don't move, take them off and make sure the hubs will turn. Repeat the process on the front if necessary to locate the problem.

2002 X5 3.0 243,000 miles
2004 325i 108,000 miles

Yeah. Who would think changing wheels would cause a frikkin issue?? LOL. The wheels are all the same size and offset. No idea how it may have happened, but it does sound like something is binding. Guess I know what I'll be doing this weekend.

keep us updated im curious .

What was the cause?

Sounds like the ABS is locking up the brake. Try disconnecting the battery.

Sorry for the late response guys. Apparently when I took the new tires to be placed on the new wheels, and the aftermarket wheels taken off, there was a spacer that the a**hole a the tire shop didn't return to me. He just gave me the wheels and tires back and kept the spacers. Guess where I'm going today??????

I hope he does not claim no knowledge.

Sorry.

So are the winter wheels OE or aftermarket? If they are the OE, which I'm guessing is true although hard to follow in this thread, your lugbolts are binding because they are too long.
Don't put spacers on the OE wheels if they are the correct staggered wheels for your iS. Just get a set of OE lug bolts that are the correct length for your OE wheels, and only use the long bolts with the aftermarket wheels.
Definitely make them replace the spacers with similar or better if they have 'mysteriously disappeared' from the shop already.