i think there are several products to mod the throttle lag.
look up sprintbooster. some interesting posts in bimmerfest and mbworld.
i have no experience with these, and frankly not too much of a prob with
the pedal in our 3.0. actually i was always rather pleased with
the ecu holding a lower gear in local driving on modest incline in D.
SD and M are noticeable improvements though for passing etc.
hell i like playing with the shifter in this thing too.