I was told today by a Porsche service engineer that it didn't do anything to the (glorious) resonator. I asked him how much it was to retro-fit the PSE and he said 2500 GBP, or if i kept the same exhaust pipes then 2100.

PSE was on my original new car spec, but I ended up getting a used car with 2000 miles on the clock (so almost new and no wait), with no PSE. So I'd love to retro-fit.

Saying that, my only concern is that I rarely use Sports Mode on public roads, and PSE is tied into the Sports button. I KNOW there is a KBA on making this permanent (ie. always on), but at the same time I like having a quiet mode for coming home through highly residential areas. So either I have to use sport mode more (which in the wet/cold is no so safe on public roads), or have a 24/7 loud car. Hmmmmm....