I recently sent in my E60 520i to AB complaining that my car is not responsive especially when you want to accelaate from low speed cruising, you will feel a brief moment that the car does not react.The explanation I got for the problem is due to the new gear box design that it was slow in locking and unlocking every time the gear shifts, particularly in low gear.Anyway, AB claims that BMW is now developing a software to rectify the problem but they got a newer version than the one that comes with my car when I got it in April 05.After the software update, I can immediately feel the gear box is much more responsive even on low gear, I got the ture feeling of driving a BMW! However, I can't wait to try out the newer version they are developig as claimed.Any E60 520i owner who encounters the same problem should go for the software update.