Bose Rewire?

[Z3R013]

I recently installed two 12" Infinity Kappa perfect subs with two pioneer 500w amps into my 01 S4 with the bose system. After the install from "The Stereo Store" the system worked good for a week, than I had to take it back for engine whine in the front speaker...they fixed that. Three weeks later I have to take it back in for the same thing in the back speaker. This time they say they couldn't hear anything and if anything its being caused by the Bose amp and the car will need a complete rewire. Is this the cause or are they just trying to screw me over? So far, this place has done two shitty installs and my system is still having engine whine. Please if anyone can help I would greatly appreciate it.

[Krieger]

2 crappy installs = shame on u. go somewhere else next time.

if u hear it thru the speaker, id think something was grounded. or isnt grounded.

My front speaker had a nasty whine, so i pulled the head unit and noticed the grounding wires were not done up right and just tightened everything down, and made everything perfect again. no more whining noise.

[Z3R013]

Thats what i figured the problem is and they took two hours to "check the grounds and wires" but didn't find anything. if they dont fix it this week I'm lose my mind. Its soo annoying!