2.7t producing just under 12 v

[Leon]

Verify where that electrical smell came from, see if something shorted
out, fuses, cabling...
Don't trust your gauge completely - get your volt meter out and verify
your voltage at the battery and alternator itself. If those read below
or around barely above 12 with no load on from lights, fan, radio etc,
it might be dying.
Sorry, wouldn't know how easy it is on those A4's, specially with a V6.

Dave