Thank you very much for the replies! You don't know how helpful your feedback is! Yes, I want to add a twin exhaust tip as:
1) Through the bumper. The problem is that I need to cutout the bumper. I am not sure if the cutout will be only from the skirt of the bumper or it will take away from the bumper too. (Are they two separate parts, or they just look like they are?)
2) Below the bumper. The problem is that I can't find a bent joint (something like 90 degree) to connect the exhaust pipe which is facing downward to the exhaust tip that will be facing backward. I am also concerned that it will hit the curb when parking, etc.
I am not looking for a new muffler or anything like that. I am not looking to increase the performance of the car or make its sound sportier. (I am actually very picky about the quietness of my car.) I am doing it mainly for looks. If I can get a muffler that will increase the HP and make it a bit more sporty (not noisy) for a decent price than I will go for it. But I am definitely not spending something like $300 on this modification.