I got my copy back in April and have had many enjoyable 2 player matches.
Over Christmas I was back at my parents and we decided to go for a 4 player game. Although the rules dictate an individual tournament we wanted to try and keep it as a team event.
I can say that this does work and, with a few tweaks to the rules, can be just as enjoyable.
-Team mates were allowed to confer on what number rider they were going to use before each heat
-If a rider has 2 opposing riders immediately in front of him (i.e. 5-1) then he is able to charge even if the two riders ahead have been involved in a charge. This was brought in as we realised that the front 2 riders could charge each other and therefore be free from being charged by the opposition based on the existing rulebook.
-If 2 riders on the same team were battling each other in the bends, the 1st card laid could not be the chequered flag card. This was brought in as races were being immediately finished by 2 riders on a 5-1 playing 1 card and not offering resistance therefore ending the race without the opposition having any chance to do anything. This is more up to personal opinion as you could easily ignore this and take the "well that's just how it goes" approach.
-An idea was raised, but not used, that a player could lay cards for either himself or his teamate to increase the teamwork aspect. This was not tried as we felt it would be pretty messy; but others may like it...