Originally Posted by TheOtherDave™

Well, a longer perf-core resonator will help cure the buzzy higher-pitched sounds. But with 2.5" tubing, expect a fair bit of low-pitched drone at cruising speeds. I speak from experience because I used the same diameter mandrel-bent tubing with a similar muffler and resonator on my last car, a 91 GTI.

IMO, you're still better off with a system like the Apexi WSII. It has plenty of flow capacity for minor bolt-ons and it does a much better job of managing sound at highway speeds.