Sign up is usually two Sundays before the event and like jamesd said the info is on the front page on the right side
Its actually the Sunday before. Not 2 sundays.
The next car topper is Aug 17 at Mill pond aka agawam river. Even though the schedule says Aug 3. It was rescheduled.
So for example the sign up thread for this tournamnet would go up at 7pm on Aug 10th. It is a 1st come 1st serve basis and once it is filled we start a alternates list incase someone drops out. Just find the thread and post a reply saying "In" Come up with a fun team name if you like.