After trolling forums and the Internet for any stories of mounting a small rig in an Audi TT sportscar, I finally gave up. Then AES had their closeout sale on the discontinued FT-1500 (a first class little 2M FM xcvr), and I snapped it up.
Just in case any other hams have an Audi TT, I though I'd do 'em a favor with a little experience.
In the console below the ash tray and just in front of the gearshift there is a small compartment with the gas cap and hatchback open buttons at its front edge. Lo and Behold! The FT-1500, with its mounting bracket fastened to it, is a perfect fit in that compartment, with about 3" of space above it for cooling. A 10" bungee cord from the bottom edges of the console just in front of the console stack brace wraps around the front of the mounting bracket with the rear of the radio in the compartment and the front edge protruding over the buttons. An ell connector on the SO-239 prevents any space problem with the antenna connector, and the power cable routes around to the right rear of the compartment, thence into a short power cable tied into the cig lighter wiring.
It's a perfect fit! The mike lays neatly and solidly in the recess between the radio and the gearshift boot, and the antenna coax routes nicely just under the console edge, out the back of the hatchback, and around the hatch seal to a glass-mount antenna at the top of the rear window. It works great, though I'll avoid running the max 50 watts so as not to overheat any underdash cabling. Now I just need to find a way to get the minor whistle out of the whip - the duoband whip I originally placed there sang like a harp at speed, and no amount of windproofing seemed to cure it, but the whip just sings very slightly. (The noise only gets bothersome over 120 mph or so)
Chances are, no other hams on the planet have an Audi TT, or somebody else would have posted this somewhere.....