Did you guys know that the AH3 (as well as AH5 & AH7) uses the heavy-duty ZF 8HP70 transmission, that is rated to handle 700nm (516lb-ft) of torque?
The actual part description is
GA8P70H With the
H designating Hybrid use, with the electric motor in place of the torque converter.
The standard 3-series (along with other BMW N20/N55 vehicles) uses the
GA8HP45Z which is rated to 450nm (331lb-ft)
Other BMWs which uses the heavy duty version are the 550i/650i750i, the
GA8HP70Z. No doubt to accomodate the additional power of the N63/N63tu V8.
http://en.wikipedia.org/wiki/ZF_8HP_transmission