Hi, this is just a thought, in terms of your description of the problem...I have never experienced this in my kluger, but I did initially have what you described when an after-market mobile phone hands free unit was fitted to my Camry. The controller unit had to be moved to stop ignition noise (similiar to what you described) being feed out of the handsfree speaker which was mounted under the dash (mine was on the steering column, but that is at the installer's descretion). Based on your description of the problem (considering it happens whether the stereo is on or off), I'm wondering whether a handsfree unit has been left in the car and not removed, because it would switch on with the ignition and could make the noise. It is just a guess, but a possibility..best to find the source of the sound, perhaps by turning the car on and reving it a bit if you can...or just having a good look under the dash for any sign of a black handsfree speaker...if you find one, the quickest way to stop the noise would be just to remove the speaker. If it was bought from a dealer, and you find a kit, I'd get them to remove the whole kit, if a private sale, an auto-electrician could quickly remove it. Good Luck, it will be interesting to know what you find