We are pretty close to completing an engine mounting kit for the LSx into the BMW E36.
The front subframe is modified to accept mounting hardware. The installation of the mounting kit is more involved and time consuming than other kits on the market, but we believe the extra work is worth the results.
Our mounting kit uses 1984-1988 Chevrolet Corvette rubber isolators which prevent vibrations from entering the car, which seems to be the biggest complaint about some other E36 mounting kits.
We believe the engine mounting package will also work on the E46, with minor changes.
The engine mounting kit will probably be less than $400, which includes the Corvette rubber isolators.
The transmission mounting kit will probably be less than $200. You will have to provide your own rubber isolator (from a 2001 Camaro), or polyurethane mount.
The 1-3/4" headers will probably be $550 for plain steel (plus shipping), and ceramic coated headers will probably be $750, plus shipping. Please don't ask about 1-7/8" headers!!!
The aluminum parts in the photograph below are for aligning the steel plates onto the subframe.


Transmission mount assembly.

Long tube headers, ready for production.

For more information, please see this link:
http://jagsthatrun.com/BMW_Order.html