The S2000 has a dual exhaust.

That said, the way the pipes are routed on the G2 you can only really fit one muffler mounted sideways like stock. You could try and fit a couple canister-style mufflers in there but it would look kind of odd from the side. Alternatively you could have a stock-style muffler and then have one tip come out of each side.

It would be custom work either way, but it's not going to hurt your performance that much like some people would lead you to believe. It is however, extra weight that doesn't make you any faster.