I have just posted the Canadian TSB2810 (= US TSB_AU004-07) covering this problem, titled "Noise from Auxiliary Port with External Device" in the thread "List of pertinent TSB's." There's a revised AUX socket assembly, connector cable, and in-line filter module that get fitted in place of the original AUX socket to resolve the noise problem that occurs when the auxiliary device is playing while being powered by the car's 12-V system.

Stan