I don't have live side pipes so my system will be a little less complicated than yours if you've got them. But I do have an under car exhaust system finishing at the rear of the car with electric cutouts that exit under the side pipe outlets. They are from Quick Time Performance and are the 3" oval ones which give a bit more ground clearance. The only issue I've had was a lost butterfly valve out of one side, which I'm about to replace. But generally they've been good. You can open or close them via a button on the dash, they are programmable, with 4 choices. I have 100% closed 25% open, 50% open and 100% open. Here's a link.
QTP » Electric Exhaust Cutouts
cheers