We had a C6 customer who had odd problems where the car battery was draining even more then the normal problems.
In doing diagnostics we traced the problem down to a product this cyberspace vendor
sells for $99 which is a simple wireless product that comes with 2 key fobs and a remote receiver that switches a single circuit on or off and used to force the baffle in the mufflers to be open when normally they would be closed
All this does is make the exhaust louder. Read the writeup and test results in the Z06 section as how badly doing this at low engine loads.
This Southerncarparts makes all kinds of claims see
Junk product When doing research we find the real seller and in fact they make a profit
selling this at only $21! You can imagine how little is in this design and reason why it is common for the receiver to get stuck in a closed / on state and dragging the battery down.
I'd also suspect at a profit made at that low price the product may be made in China
Look closely at Southerncarparts image of the key fobs, notice the red marking at the bottom edge and then with this vendor and the same exact markings and the key holders are the same.
Real Maker Here is the image of their $21 product
No sense if doing this to be paying someone many times what the real retail price is