What's the red light on the dashboard mean?
It means there's not enough electricity going to the engine. You see it when the car has stalled, or hasn't started, or maybe when it has broken down on the way somewhere.
What to check and fix
First, open up the engine bay and check none of the wires are loose (make sure the ignition is off before doing this - take the key out of the ignition.) Also have a look under the bonnet at the wiring loom and see if anything looks like it's fallen off.
If there's nothing loose / fallen off, take out and charge up the battery
If the car now starts, but only goes for a few journeys before the battery goes flat again, you either need a new battery (they do wear out after a few years) or new generator brushes, or a new voltage regulator.
It's cheapest to first change the generator brushes, then if that doesn't work, buy a new battery to try that. If it's still going flat regularly then replace the voltage regulator. When you put the new battery in, charge up the old one and keep it in the car for a while - you can jump start the car from it if the power in the new battery gets low.
If the car tries to start, but struggles and/or churns:
- Check the spark plugs - do they need cleaning?
- Check the HT leads for corrosion
- Check the distributer cap for corrosion and dirt
- Check the points to see if they're worn out
- Check the timing - it should be adjusted every few thousand miles / every year
It's probably worth changing all of them if you're not sure of their condition, as they're pretty cheap and should be replaced pretty regularly (i.e. every several thousand miles or every couple of years, whichever comes sooner.)
If all this doesn't work, either drop me a line or you'll probably get better help if you post on the Volkszone Mechanical Tech forum.