[parapaul]

You mean the yellow plastic bit? That's just connected to the trigger underneath the normal shifter and locks it in Park. With the M5 shifter you just don't have the trigger - as soon as you put your foot on the brake you can move the 'box out of Park.

I cut the leather gaiter off the M5 knob - but I cut mine a bit too short. Are you planning to reuse the stock boot or are you fitting a new one? Either way, leave enough of the M5 leather to give a good overlap with the gaiter that's attached to the car. Mine is a quarter of an inch short and I wish I'd thought it out a bit better before I started cutting!