Put the tuned pipe on! I also have a Max St but its a pro that came with the tuned pipe on it. You can adjust the tuned pipe. Press the pieces together under the coupler and get more low end torque. Pull them apart 3/4" and you get better top speeds. I press mine together off-road and spread it when on road. You do have a diferent engine than mine but I think it works the same.

As far as your body is concerned. If you cut your body right the tuned pipe looks cool. All you have to do is let the little tube stickin out of the side of the exhaust breath. Also the stock max st bodies are shaped to go around the exhaust so it isnt seen.