The car was having starting problems. I found it was a sticky fuel pump relay. Took it apart, lubricated, reassembled. All OK now.
Whilst looking for a solution, I found a comment on a Czech Skoda site that said "after being left unused for a few days, fuel pressure will have dropped to zero, so before cranking the engine let the ignition switch stay on second position for 10 seconds to allow the fuel pump to operate and return full pressure".
I never knew that before.
