I own a Black 2007 Camry LE.
The Sirius Stratus unit I had installed produced a very annoying buzzing/whining noise. I used the AUX input down in the cubby hole and powered it with the cigarette lighter.
I bought this Ground Loop Isolator from my local RadioShack ($16.99):
http://www.radioshack.com/product/in...tId=2062214&cp
It fixed the problem right up and the sounds quality is excellent.
I did have to purchase a Y-Cable and a Mini Jack Coupler to get everything to fit.
Total cost : $16.99 (Ground Loop Isolator) + $6.79 (1/8 Y Plug) + $3.99 (Mini Jack Coupler) = $27.77 plus taxes
You can try this out and see if it works for your car, if it doesn't, just return it.
Hope this helps.