Help! I don't want to sound like a bumblebee.

[OgDogg]

First off I feel I should explain my story. I'm not an import guy. I like old American made muscle cars. I recently purchased a Yaris however, due to me moving 40 miles away from my job and needing a gas sipper. I thought the Yaris would be a fun little car to have and would be cheap to customize. So far, it's living up to my expectations. Here's my issue...

I want to put exhaust on it because I've already done the intake, the speed limit is 75 where I live and I could use the extra power getting up to speed. The problem is I've heard kids with their civics with exhaust and they always sound like giant mutant bumblebees. Ideally I'd like my Yaris to get the performance of upgraded exhaust without the loudness. Kinda like a mini muscle car type sound. Quiet, deep and adding performance. Any experts know the best exhaust for me? Or should I just hold off completely and stick with the stock?

My final concern is that I have the stock ground fx kit. The current exhaust bends down behind the kit and can't even be seen. Would I have to cut a hole for the new exhaust?