My 99.5 A4 2.8 Quattro (85k mi) occasionally generates a lot of heat
in the driver's side foot well. I don't know if this occurs on the
passenger side. It occurs with the climate control absolutely off an
utterly deactivated--no heated air is issuing from the foot well
vent(s). The surfaces in this area clearly feel warm, as though engine
heat is excessively penetrating the firewall.

It only seems to happen after extensive driving, but even then only
seemingly sporadically, which is a puzzle. Some days after extensive
driving it occurs, others it does not, I think--I've not done a
scientific study. It also seems to only be perceived when the outside
temp is above about 70 deg F.

Anyone else have this problem? Sometimes it is so uncomfortable I have
to turn on the A/C.

I seem to remember somebody in the Audi newsgroup reporting this
problem with an A6.
Dave