We landed in Frankfurt on a Sunday then went to an ADAC office on Monday morning to get the papers. From there a bus back to the airport and we had our bikes on the road that afternoon. Super easy. I don't recall it being nearly as expensive as Knopf is quoting either.
If you are landing at Schiphol you could check with the Dutch version of ADAC, the ANWB. They should be able to sell the Green Card as well.
I had my R100GS breakdown in the Netherlands and my uncle called the ANWB. Five minutes later a guy showed up in a small station wagon full of tools. 20 minutes after that he had found the wire that had shorted out on the frame and repaired it. Showed him my CAA card and everything was cool. Wow. I think if I would have called CAA with a bike problem I would have been lucky to have a tow truck show up!
Redwood Meadows, AB
'03 R1150GS Adventure
'84 R100RT 141,000 km (Dad's!)
'89 R100GS 250,000 km (and ready for another continent)
'07 R1200GS Adventure 100,000 km (just finished Circumnavigating Asia)