State of the art
What computer manufacturers developed on Windows
The aim of using two graphic cards is mainly to provide a good compromise between a powerful card whose power in needed only when running demanding programs, and an integrated card, which would not be well suited for those usages. On Windows, the load between the discrete and the integrated card is automaticly balanced, when the right drivers are installed.
To be expanded / corrected
i don't get what you're saying. Is it the montuing piece behind the speaker or the speaker baffle/grill? I suggest getting to the speaker (may have to open the door panel- easy) and reinstalling the speakers with weather stripping or double sided tape. That will help "sit" them better and create less vibration. OR buy some dynamat and put them over the speaker opening. Simply cut a hole in the dynamat to clear the speaker. U should be ok. but the speaker needs some sort of a gasket to sit right and they usually don;t provide it in the factory. technically u could take it to the dealer since the car should not be doing that with a stock system but it's a camry millions built on an assembly line. u always get minor issues like this. wouldn;t hurt to call them to be safe. I mean the bass is only on 2. good luck