[RKDinOKC]

Got one for the Cayenne called Durametric. It talks to all the Porsche computers. It's under $300 if you have less than 4 cars. Basically it's just PC software and a cable like the Porsche factory diagnostic tool.

For the 928 got a SharkTuner. It comes with programmable chips for the 2 ECUs and works thru the diagnostic port. Also uses a wideband O2 sensor and lets you do custom tuning. You can drive around and it records what is going on, then you can use that data to automatically tweak all the maps or manually tweak them yourself. Can also put a switch in that uses a different set of maps like if you wanted to run racing fuel. A lot of guys just make it a valet mode that limits the revs.