Do you think the issue is anything to do with the link I posted for you regarding the corroded wiring ?
Also as I'm sure you are aware Audi do look into warranty claims even if out of date.I had Audi Uk give me a 90% goodwill gesture on my 8p 2.0tfsi quattro when the engine went bang.It had 74000 miles on the clock and it was 6 months out of the three year manufacture warranty...
As for being just an S4 I have to say that the one I had as a courtesy car a couple of years ago was a magnificent car and was lovely to drive..Here is a pic..
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