The below was my response to a post from 2007 asking about a racing
engine while driving down the road.  I would like to know what others
experiences are and their input to this post is appreciated.

If you care to respond via email use midecaseya2@yahoo.com

Thanks!

I too have had that experience.  US model 2005 ZX3 with an automatic
transmission and a 2 liter engine.  The vehicle was appoximately two
months old with 3.5k miles.  

While driving on a two lane road in southern Michigan, (early May, cool
evening, light mist), the dash lights and all gauges "flashed" a couple
of times.  On the second "flash" of the dash lights I noted all the
gauges going to the max as well.  

The Flashing dash lights were not on and off but rather regular
illumination and VERY bright flashes of appoximately a second duration.
In my experience as an engineer I have wittnessed the same during a high
voltage spike.  Possibly something in the alt/regulator?

Anyway, I lifted off of the go pedal while the damn thing floored itself.  
After about 5 seconds of bumping the gas pedal and then the brake pedal,
I had the presense of mind to simply turn the key off and I then braked
to the side of the road.  I turned the key back on, the gauges and all
seemed to zero, except for the eng temp which read actual temp.  There
was no repeat of the flashing dash lights and gauges slewing around.  It
restarted and ran normally except for the check engine light which was
now on.  The ONLY thing that could have taken the gas pedal to the floor
was the cruise control activating to full pull on the throttle
body/linkage.  

I carefully drove home and in the am took the car back to the dealer
where I explained the problem.  I used a loaner car for the three days
the dealer took to recieve and replace the "transmission position sending
unit".  That was the only fault the computer returned.  I have over 75k
miles on the car now and have not had a return of the same problem.  

I have had to replace both rear wheel bearings and three sets of tires in
75k miles.  The factory settings on the rear are stupid and guarentee
that the tires will wear out in 20-25k miles. I have had mine set to 0
degree toe-in with me sitting in the car and the feathering/wear has been
reduced to a more normal pattern.  Current tires have over 30k miles and
still have 50-60% tread left.  The excessive toe the factory quotes is
probably the cause of the wheel bearing failure as well.  

Another issue with the factory toe-in is VERY dangerous.  With such a
light car, while driving in weather, it is possible to unload one side of
the car or the other.  That is, get one tire to plane on water or slush
and the other side of the car stays planted.  When that happens, the tire
on the loaded side of the car, (the side NOT planing) will push against
straight travel and can (did in my case) cause a spin. At the factory
setting (as recieved 2.5 degrees toe-in on both sides!) it shot the rear
end to the right when the right tire unloaded on slush. Compounding that
problem is that on most roads, the big semi's typically have left slight
depressions in the tarmac that collect a bit more water than the crowns.  
A small car like the Focus does'nt ride equally in both depressions so
the likelyhood of having equal ammounts of water/slush under both sides
of the car is less than that of an bigger car/truck and increases the
likelyhood of a spin because of the above.  Add to that the tires wearing
very rapidly (worn tires plane much more easily than fresh tires) you
have a great recipe for disaster.

Other than the above I am extreemly happy with this vehicle.  A bonus for
us BIG guys, 6ft 3in tall is that I actually fit in the damn thing and my
brother, same size can travel with me.  Loads of interior room, (Head and
Foot) in the front seat and with the two door entry/egress is not the
twist, bend, lurch activity typical of most small cars-big people
matings. Don't even talk about the rear seats....  My five year old
grandson does'nt fit now, I can't wait until he is ten.  lol.