New Car, Stock, Audio/Electrical probs!

Hey guys, I figure this would be a great place for advice so here's my situation.

I purchased a new 2005 Nissan Maxima in late August and have been having a serious audio/electrical issue in the car. It came with a Bose premium sound system. After driving the car for 10-15 minutes with the sound system on at normal listneing volumes, the front left speakers (top and bottom) go out and make a very high pitched eletronic sounding buzz. I turn the system off and after a few minutes that buzz goes away and normal audio comes through the speakers again.

I'll turn the system completely off (with the car still running) and the sound comes back about 20-30 minutes later! It is very annoying and seems to be a pretty complicated issue. The dealer has ignorantly replaced the speakers (on that side) and the radio unit itself to no avail. They cannot figure out what the problem is and will not continue to replace parts unless they can induce the issue on the fly.

Temperture seems to have a bearing on the problem because when the air got cooler the problem went away for a week or so. Now that the weather is hot again ( I live in souther Cali) the issue comes back in the circumstance I mentioned above. What should I do? Does anyone have any insight on this and what could be the cause to this? If it's not the speaker or head unit, what else could it be?

Could it be the amp? Since the problem occurs when the audio system is shut down (but car is still running) shouldn't there be no power sent to the amp?

Is it grouding/wiring? Or something else? Help!!

If it's a new car I say go immediately to your dealer and demand warranty repair and/or replacement until you are satisfied.

I'm trying!!

But Nissan Corp said they will not allow anymore repairs/replacements unless they can induce the problem and hear it! Like I said it is intermittent and cannot be induced on command.

The dealer unplugged the amp and we'll see if the problem continues. If it doesn't (in the next day or two) they will replace the amp. Let's hope this works.