my problem started last year, when speedo started to fail intermittently on a long journey, then would be ok when cold and on short journeys. this got worse and stopped working completely. took it to main skoda dealers, and was told it needs a new speed sensor, but it could be the clock unit in the dash, other symptoms include fuel gauge going up and down, like the power being turned on and off and engine and power steering warning lights coming on and off in the dash, also near side stereo speaker goes on and off when playing tapes, but technician said this could not be connected. to cut a long story short, the car has been into skoda 5 times in the last 7 to 8 months for this fault and has had 2 speed sensors changed, the wiring to the sensor cleaned up, the ecu changed and recently the clock unit in the dash replaced. I got 2 miles down the road with my new clock unit and it went off again and i am stuck with the same fault. Can anybody help me with this, or has anybody had the same fault, skoda say they have never heard of this problem and i think the people at my local dealers have no clue how to fix it. Its booked in for the sixth time so i will hold my breath. thanks.

Not has it before to be honest but i'd be looking for something like a loose earth somewhere. Checking the current flow diagrams should indicate if they systems have anything in common.

A very long shot here - check for water ingress into the wiring loom that runs along the pasasenger chassis rail from the battery to the interior.

Remove some of the binding tape and see if it is full of water.

Does the instrument pod have its own voltage regulator? Is that faulty?