Thank you, Mike, you summed it up perfectly.
My guess is goes into the direction of a faulty pickup, or ignition amplifier, because the symptoms got worse progressively, which could indicate a slow deterioration of a electronic component.
Anyhow, he car is now in for repairs and I will let them figure out what the problem is and replace everything necessary. I would not say „money does not matter“, but I‘m willing to pay, in order to have a reliable car. Anyway, after the crisis our money may be worth less, so why not invest it now…
Sunny greetings,
Ivo
)