Buy that and have it installed at RMP motors. http://www.rmpmotors.com/
If you talk to a BMW they will deny there is a problem with the cars and they've never heard of it. A quick google search on "E46 subframe crack" proves otherwise. It's actually not the subframe that cracks it's the mounting points on the car that are made of sheet metal that crack but everyone refers to it as the "subframe issue"