Well, if you plan to run straight pipe, it's a good idea, that's what we did on out CTR, we just ran striaght pipe, but to meet the 103bd level required for SCCA, we had to add two little tube style resinators.

If you're planning on using a muffler, you're really better of with just one, although I guess it depends on what you want to accomplish. Keep in mind, the more resinators, the more restriction, and therefor less hp. Any way you slice it, your car won't be that loud under boost, you'll probably hear the charger over the exhaust....

Later,
Aj