Monday I joined the AA and phoned in for an insurance quote. Arranged everything over the phone. Tuesday I returned the rental car, and now I am on my own. No more safety net - now I really have arrived.
Now the trouble starts...
Wednesday, I play with the electric windows; then the rear right window does not move up anymore. In the evening I remove the door panel to access the interior parts of the window mechanism, but no use - I cannot lift up the window manually.
On weekend I find the equivalent of the US Pep Boys: Halfords. What a relief - now I can browse for all these car goodies. I find a few things: voltmeter, wires, clamps. Fully equiped, I now tackle the electrical issue. Turns out that the motor of the window works fine. I am able to wind it up again by connecting the motor directly to the electric power. Then I disconnect it - I will tackle this problem at a later time and repair the window switches then. For now, the right rear window is simply just disabled.
A few other things do not work at this car: some of the switches on the dashboard do not have a background illumination - so at night I do not see some of the settings there. The right mirror motor does not pull the mirror in the vertical direction - I have to adjust that by hand. The interval wiper setting does not work: the front wipers do not operate at all in the interval setting, and the rear wiper does something weird, whenever it thinks it should - and then stays in an arbitrary position. No huge problems, just minor annoyances - and I am willing to deal with them, for that great price.