Found something of profound interest to myself and anyone else looking to put a remote start on the new A8L models (2004 and 2005). The link below gives the details on the bypass kit that allows success:
http://bypasskits.fortinautoradio.com/bypa...?bypasskitid=24
Additional information:
1 - This is the only company I have found so far that makes a bypass for the Audi A8L (also fits the VW Touareg and Porsche Cayenne): Fortin Auto Radio in Canada. When you call them they begin speaking in French but speak English just fine after you reply.
2 - They make their bypass for only one manufacturer's remote starter kits: Firstech of Seatlle, WA. Fortin sells both the bypass and the remote start kit together.
3 - Firstech's starter kits all use the same control module. You get the attendant remotes and matching antenna for the type of access you want (basic, 3000 feet, two-way remote that shows the status of the start, etc. - their top of the line is a rolling frequency thing but I've been told that it's slower than the simpler models). See their website for difference in models, even though they all use the same control module.
4 - Fortin sells two different models but if you want a different one you can contact Firstech directly (interesting name for their website considering the product and company name, but...):
www.compustar.org. I bought an upgrade for $60 to have the 3000-foot range. Not a big deal, and if you live outside an area where they have distributor/sales/install/shops, they'll sell to you directly. Their starter kits seem to be high quality (guess I'll find out if not - but I've been impressed so far).
5 - The install is very simple. Any experienced installer should have no problem and it can be done in a couple hours max.
6 - Fortin's kit includes a modified "barrel" which is the ignition part where you inert the key. You pay a $250 deposit (the cost of the part) and after you return your original barrel they refund the deposit. You can view and print the installation instructions right from Fortin's website.
7 - As mentioned, the starter kits are sold together with the bypass kit by Fortin. So go directly to Fortin. The cost was very reasonable in my opinion(!) at under $300. Then if you want an upgrade to the type of remote/range combination, talk to Firtstech.
I found a local installer to do the job. I would have been happy to give them the info, let them become a dealer if they wanted, and then buy from them, but they alreayd had a number of lines and didn't want to take on another; doing the install (under $100) was no problem for them, however.
I have had remote starts on the last 5 cars I've owned and loved them. I find them most practical given that the climate here in the mountain west is both cold in winter and hot in summer. Given the hassle I went through trying to find a way to get one installed on this A8L (2 shops gave up after trying for a day and numerous others had no answers and weren't even interested in trying), finding this solution was a very fresh breath of air.
Hope this is helpful to others out there.