I received my new Stillen catalog yesterday in the mail.
They devote the first third of the thing to 350Z, G35 Coupe and
G35 Sedan. They will be offering a computer upgrade for
all three. I got excited and called them up to ask about the
computer upgrade. The pic they supplied shows it to be a
piggyback module that plugs into our ECU. Well...
Of course it has not yet been officially released. The Sales
guy could tell me nothing about it. It would be great to be
able to simply plug in a module to upgrade, unplug it for
dealer visits. I'm anxious to hear more about it.

2003 TwBlue 5AT Sedan, sunroof,
Graphite Leather, splashguards, HKS exhaust,
14 wire Grounding kit, 350Z duct, Stillen CAI
Underbody rear diffusers, Drilled alum pedals

 

That's how the Wetterauer chip worked for my Audi. With the Wett chip, you sent in your ECU, they modified it so you could plug in or plug out the original program. In 4 years, I took it into the dealership without ever swapping them, but it was nice insurance to have if something ever went wrong.

2004.5 Coupe/5AT/Ivory/Everything but chin spoiler/Z Tube-Popcharger