Dale
  I can tell you from experience that the Audi problem was real. I

don't know what the problem was but it wasn't small close peddles.
 I had an Audi and experienced an uncommanded acceleration.  Here
is what happened.  I turned a corner on a city street and started
to accelerate and the car throttle body went "Wide OPEN"  the
RPM went   to about 6K.  I stood on the brakes and it was still accelerating
 and about to hit the car in front of me so I kicked the transmission
 into neutral and without a load the engine RPMs pegged for a split
 second and then dropped back down to idle.  I parked the car on
the side of the road and called the local Audi dealer... Keep in
mind it was "Not" under warrantee. They immediately picked it up,
 gave me a free rental and fixed it for free.  Oh, this was the
4000S model and not the 5000 model car that was suppose to have
the "Problem".  I don't know what was wrong with it but I do know
it wasn't "peddles"

 Mike C.

Not necessarily calling bs, but I don't get it.  There's not a car
made that can accelerate as fast as it can decelerate.  That
implies  that the brakes are able dissipate more energy than the
engine can  deliver.  I believe the engine might have gone to WOT,
but I have a  tough time understanding how the brakes wouldn't be
capable of still  hauling the car to a stop.  One factor is that if
the engine is at  WOT and you pump the brakes, the booster would
quickly lose vacuum  and so you'd be without the brake assist. It
might take a heavy foot  to get much braking effort, but the same
braking power would be available.  And, I can imagine that it would
be surprising as well..

Matt-

I have not tried it Matt but one can "fade" the brakes.
This is when the pad material gets so hot the coef. of friction
goes  way down. It is a runaway situation. The longer you hold the pedal
down with full power the worse the brakes get. Also brakes boosters
work on vacuum. WOT vacuum is near atmospheric pressure.

Brake fade is very common in road racing. One of the first things
you need to do to convert a car to a road race car is upgrade the brakes.

Paul Lamar

--
I doubt my situation caused any brake fade as it was over in less
than 5 sec... I was on a 30 MPH zone and only about a car link and
a  half from the car in front so by the time I stepped on the brake the
distance was closing very fast and I immediately went into
neutral... It was over very fast,... I remember starting to change
direction toward the curb to steer around the car as I threw it
into  neutral... No Idea what caused it but it was real.  Not that
the  following has anything to do with the "Audi issue" but for the Prius
problems... I personally think that there might be some EMI
issues... They certainly don't shield those cars or test them to
the  level we do in Aerospace and I bet they have missed a corner
EMI  condition... Which would explain the "Ghost" in the system.

Mike C.

In a road racing situation the brakes can fade in a fraction
of a second. You come into a 20 MPH corner at say 80 MPH (117 FPS)
and stand on the brakes.

The brakes can fade in 100 feet. Of course if you did not
brake then that cannot happen. That scenario is for those people
that tried to stop the car by applying the brakes.

Paul Lamar

Trying to back out of a parking stall and putting it in reverse
says brake fade was not an issue. Mike's problem could be different.
A lot of heavy brake use precedes brake fade. Three laps of the old
Edmonton International Speedway
(remember that one Paul. I corner marshalled a few times when the
Chapparal was there) and my RX 3 had no brakes. 130 MPH into corner
one. Yah it can happen quickly, usually on a heavy car and a down
hill. Drag racers used to brake torque to warm the rear tires. Held
the brake to the floor and the gas pedal to the floor. They usually
backed off the rear brakes a bit so they did not hold as well. Then
they could really melt the rear hides. The front brakes still held
the car back. I still say the brakes SHOULD hold the car back. I
could see some creep, but not the unimpeeded acceleration described.
If this did happen, the brakes should be really hot when the car
comes to a rest at the end of the event.

Dale Davies

I think the term unintended acceleration applies to a wide variety
of situations. I agree that from a dead stop the brakes should hold
the average car from moving as there is no real energy going into
the brakes. The lady in the parking lot could be faulted for not putting
her foot on the brakes when she selected reverse but how many
of us really do that all the time?

Paul Lamar

With an auto trans??? Aways!!!

Dale Davies