noise in front left

[vnikulin]

2003 subaru wrx, bought in may car, car was in accident prior to purchasing, nothing serious, seems like sliding damage from right side, subframe looks un-touched

here is the problem:
there is a rumbling vibrating noise thats coming from front left, noticible after ~55mph up to ~75mph (seems to go away after 80), used to come in sort of waves not constant could be heard more when highway curved right, but gradually grew into constant noise.
took car to local dealer in NY and after 2 attepts to diagnose and than 2.5 weeks spent on car they replaced some gear parts in tranny (the list was 2 pages long) and didn't fix problem, they claimed that bearings were diagnosed and normal, and that noise was comming from tranny....
just for the hell of it i rotated wheels to see if MAYBE bent rim is causing problem but that wasn't it.
oh, there is no vibration in steering wheel (that and rotation eliminates possibility of lost balance weight) but u can feel it in the floor, even on passanger side and its pretty loud especially lately.

any advice would be greatly appreciated !!!
thanks !!