For a 2001 Volkswagen Cabrio and a Falcon 2 tow bar you can use base plates # 521227-1 that you have referenced. The tow bar arms will pin to the base plate arms. I have included a link to a video showing a typical installation of the tow bar to the base plates for you.
For the 2004 Toyota Echo there are no base plates available. You will need to consult the vehicle owners manual for both vehicles to learn about the proper towing procedures.
For the Cabrio you will also need safety cables... view full answer...