Ya you'll lose some back pressure. Our cars have a pre muffler located roughly under the front seats then a resonator then the muffler at the rear. I straight piped my car for a grand total of 3 days! It was very very loud. Right now I have two resonators, a 12" tube and a 18" tube. The shorter one is under the drivers seat area and the longer one is under the rear seat area. It's not overly loud but people tell me it's loud. To be honest before I had the supercharger the Injen intake made more noise than my exhaust set up lol.
So all in all I'd recommend a single 18" resonator located close to the drivers seat area. Our cars tend to drone a lot when cruising. Otherwise at WOT straight pipes are the balls if your ears can take the beating!!
Sorry for the long response hope this helps
Here's my car straight piped (soooo much louder in person)
http://youtu.be/ELEem5RhEpMHere's the car with my current set up( louder in person but for comparison sake it'll do)
http://youtu.be/DfisjiEnaDQAnnnnd here's me playing with a Ferrari, I've run into him before so we've done this a few times lol
http://youtu.be/27p0QUU8YFM
Posted: Thu Mar 07, 2013 9:03 pm