what sort of motor do you have,,,i have a 5 litre and i took off the two mufflers and twin pipes and put on a panther 2 1/2 system straight through from cat back,sounds beutiful not too loud but a nice v8 rumble ,i do a lot of country miles and when i am sitting on 110 klm it is nice and quiet inside until you squeeze the pedal a bit
cheers fergi