Go for it man, you can add a muffler later. No muffler on a turbo car leaves alot of pipe for resonance. The first time you have to spend several hours on the highway and your head feels like its gonna implode, you will change your mind! lol.
Ill get a sound clip at some point for you, I just put 5 gallons of E85 in it so I don't wanna get on it too bad.
Ill take photos, but my exhaust has that type of muffler on the end and TWO resonators under the car. Its loud, sounds good, and very tollerable on the highway.