Germans are usually very law abiding. This is a big deal for them. I think this demonstrates that folks think that the balance between living life with its attendant risks and fear of CV19 is overdone in favour of the latter.
The 20% upfront is on line only, that may be why they didn’t mention as they wanted to sell you a service plan
if your A service was part of your service plan, cancellation may not be as financially attractive as you have to pay full price for that A service
brake pads and discs, wipers, MOT...