2004 X5 4.4i Loud bang from rear

[PrOLiNe]

Just want to say thanks for all the info on this site Just bought a 2004 x5 4.4i with 60k on it. Drives like a dream. Coming from Ford Explorer's, will never turn back..LOL!
Anyway..4 times now when I slow to a stop, right when it stops I feel a slight lag like the car wants to go forward a bit first. If I hit the gas before that slight lag is over it makes this loud bang from the rear. Almost like I neutral slammed the thing. I read somewhere about rear carrier bushings, but doubt its that otherwise I would feel something not right as well when shifting under some acceleration I would think. Best way to describe is to take a car (not the beamer), rev it up in neutral, and drop it into drive.
Any input would be appreciated. I have a one year GE powertrain warranty, but want to know where I stand before taking it to the dealer.

Thanks