Dutch Trivia

[Leo]

On a Dutch F1 forum, we play a similar game like this

My latest question there, seems to be quite difficult, so maybe an international audience is more successfull. Here it comes:

What is the similarity/connection between:

1. Wolfgang von Trips <-> Gunther Bechem
2. Heinz-Harald Frentzen/Michael Schumacher <-> Louis Chiron/Rudolf Caracciola
3. Rene Arnoux <-> Tony Brooks <-> Nigel Mansell <-> Stirling Moss <-> Nelson Piquet <-> Didier Pironi <-> John Watson
4. Norisring <-> Circuit Mexico City
5. Graham Hill <-> Gerard Larrousse

Answers like 'they have the same nationality' or 'they once drove for the same team' are not correct!