Rep Power: 0

I recently had my front bumper changed due a small acident. Now the left side, whenever you accelerate between 20-40 mph, it will start making this vibrating noise. Similar to a screw being lose and vibrating, but much stronger.

Any idea what it may be? I took it back to them and they didnt take the bumper out and put it back in to see. they said they checked the car but that was it..

any ideas?

Thanks
N41