Well, one thing that I pointed out to some folks is that the way that the 12- and 20-year rules are written, it could be argued that it only applied to the ProRally Championship (i.e., accumulation of points) and not to entry in ProRally events.
Specifically, Article 10.1.E says "Age limits of vehicles for SCCA ProRally Championship competition ..." and then lists those limits.
That Article could be interpreted as a limitation in the competition for the ProRally Championship, which is an accumation of points from a minimum number of events, not as a limitation on competition in events. This is similar to how a competitor can be excluded from the ProRally Championship because he did not enter and participate in the minimum number of events. Just because a competitor doesn't plan to run the minimum number of events for the championship doesn't mean that he can't enter ProRally events.
This has been pointed out to SCCA officials, but I have not received a response about whether they consider this interpretation valid.
alan