Don't use the BOSE. Use a y-pipe and preferably downpipes. The noise won't be a problem then.
It is worrying sometimes but they all do it. I suppose a rally car doesn't sound like its roadgoing brother but then if you want to be able to handle 650bhp and 600ftlb of torque with 200ms gearshifts in essentially a manual gearbox then its bound to be a bit noisy. Rather have noise than an Auto