List of faults, are these all from Rev C problem?
The rear passenger side light on our 2001 156 doesn't work unless you fiddle with it, otherwise it just glows dim all the time, which I have read points to a faulty Rev counter and the bulb warning light is permanently on.
Other problems that I hope are caused by this are:
The front passenger sidelight doesn't seem to be working
Headlights seemed bright (MOT'er comment)
Also no headlight pattern on either side
License plate lights are a totally different brightness to each other
The other problem which I think is unrelated is that the car ticks over way too quick and the engine management light comes on quite regular and there is a noticeable change in the cars performance when it does.