Bmw 325 shifting noise

I have a 2004 bmw 325I and i notice a dull thudding type sound when shifting into and out of the first 3 gears. The sound is muted and is similar to the sound encountered when driving over a small bump. It appears to be coming from the mid to rear of the car. Has anyone else encountered this, and if so any idea what might be causing this?

I’m not quite sure why you have posted this question for a second time, but I will give you the exact same answer that I posted in response to your first query:

I think that it would be a good idea to have the U-joint(s) on your driveshaft checked. It sounds to me like a U-joint is badly worn.

I would agree in part.
These cars are prone to failure of the guibo joint. It’s similar to a u-joint, but it’s made of rubber. It’s found on the output shaft of the transmission (the exact location of where you describe the noise is coming from).
It seems unusual that it would fail after only 4 years. Do you have a lot of miles on this car?

I only have 58000 miles on the car, if this joint is the culprit, would this be cost intensive to fix?