I think this may be helpful.

Clutch delay valve and delay in starting from dead stop.
The X5 has a clutch delay valve whose purpose is to make the clutch feel smoother and to protect against damage during some types of agressive driver clutch use. Some people like to remove it or disable it and claim that the result feels more BMW-like. This should affect every X5 and thus seemingly isn't worth checking for on new vehicles before buying them, except one person reported annoying delayed launching from dead stops on his vehicle that he did not detect on the vehicle he test drove. Several people thought it was just the clutch delay valve in action. See thread:

I copied from http://ksl.stanford.edu/people/kpfle..._problems.html