thought I should join in too! I've JUST received my letter today regarding the retrofit of ESP. They're charging us Canadians $800. The letter is pretty much identical (US/Can). Anyways, as most of us NorthWesterners know, November/December is TURBO SEASON(and of course the rain as well)! is it REALLY worth it having our vehicles sent it for the retrofit this time of the year? I never thought I'd want ESP in the first place when I purchased the vehicle, since I was afraid I may be 'restricted' with the ESP in my driving. I still ain't quite sure if the ESP turns on by itself when the car is in critical condition EVEN if its turned off, meaning its basically automatic? And how sensitive is the ESP system anyways? I've been trying to read the UK forum, but don't seem to find any information in their search. Oh well.. pretty tough decision here.. sorry for the pointless rant :)

You can switch ESP on or off from the dash...

If the Canadian offer is like that in the US it looks like the question is moot as your TT isn't showroom. In the US chipping and things like Stoneguard make you ineligible

When ESP is turned off it is off and will not turn on again until the car is restarted or the ESP is manually turned on. If you turn it off and get in trouble it is not smart enough to know to come back on automatically. Whether or not you elect to have it installed is up to you. You may wish to think of it similar to ABS - for the VAST majority of drivers it is far safer to have ESP (and ABS)- in the hands of a professional who can intentional dial in over / understeer (and consistently threshold brake vs. ABS), ESP can detract from extracting 100% of the car's potential - but that's when you can elect to turn ESP off.

One may infer from the letter, or be told by an AoA spokeman or dealer that exhaust mods are not allowed, but they are not specifically excluded in the letter, and IMHO, should pose no problem to ESP as there is no input to the from the exhaust that should affect the ESP unit. What AoA is trying to preclude is problems from different chips, electronic mods that may affect the RF spectrum of the vehicle, or suspension / body mods that would provide different than anticipated input to the ESP unit.

other posts on this and the uk TT forum

Graham TTQ 225 Wett

ABS is ABS (unless fuse is removed). ESP - off is off! Two totally different, but interrelated devices. ABS works under braking only, ESP works under all conditions - braking, turning, accelerating(unless turned off).