I just recently put on the Megan Racing resonated test pipes (ebay special $95 + ship) and I was actually happy with the sound when combined with the UT y-pipe and stock exhaust. I had the pipes on for a few days and then became aware of how serious an issue running catless in CA can be, so I had second thoughts (i.e. wimped out =) and decided I might as well spend the extra and have some peace of mind knowing my cats would pass smog (not concerned about visual inspections).

So I head over to Gruppe's and pick up a set and did the install a few hours later. The sound is pretty similar to the resonated test pipes, but slightly more tame and quiet when cruising. There is absolutely no rasp or drone, and they sound great under throttle. There is also that little burble when you let off the gas and the RPMs drop to idle. So far I'm very happy with this combo, and think it's just about the perfect balance of power and sound for those wanting to keep the stock exhaust.

The quality is excellent, with machine welds and high quality metal internals. The install went very smooth and the flanges fit perfect with very little adjusting to the ypipe required.

There is one problem that I know of on the G35c which is due to the large size of these cats. The pipes sit fairly close to the underbody and sometimes rub due to engine torque (I only noticed it in reverse). I actually saw this as a potential problem before I installed and hammered the underbody up a bit, but it wasn't enough. I may just try some exhaust wrap and hope that solves it, as I've already done cats twice this week with rhino ramps and it's not exactly a fun job. This may not even be a problem on the Z.

BTW - the Megan Racing pipes are for sale if anyone is interested. I'm selling these at my cost which was $115 shipped. They are in like-new condition and include all hardware and gaskets.