I have a Stage 2 (Exige S/C) exhaust with about 1300 miles on it.
there is the Von Hep 11lbs (loud) and the 2bular (6 week wait and $850 after shipping)The only exhausts under 15 lbs are from arquay, the single tip is 9 lbs, and the dual tip is 13lb, both exit above the diffuser though. Not too sure you'll find a sub 15-lb system that exits through the diffuser.
I have an 07 Exige s so I think the diffuser hole is already big enough, correct?Can you trim the diffuser exit hole?