Hello - I just picked up a 2010 Panamera S and would like a more aggressive exhaust sound for the least I can spend (not worried about HP). I've searched everyone and can't seem to find an inexpensive muffler only option. So the other option I'm now considering is keeping the factory exhaust and just adding an electric cutout exhaust so I can choose when I want serenity or sound! Any thoughts on:

a.) muffler only options (that are cheap!)
b.) where to buy a high quality exhaust cutout

Thanks!