Thanks guys!
But all the credit should be for the Toyota people who came up with so many different connectors that they will only fit the right way. It is realy amazing, and it works!
Last tuesday I bought some more Aygo parts.. Radiator, front wheelhubs, alternator, fuelpump (including fuel level unit, smart!) and another piece of wiringloom (the part used in the back of the Aygo) to connect the fuelpump!
Poured some petrol in a bucket
dropped the pump in... and tried to start. Nothing happend
. After connecting all 7 (!) earth points of the wiring, the engine came alive