Tom, this is only a suggestion but I think one thing that should be important is to include all the colors offered on the Crossfire in each calendar. No matter how the voting adds up.
I could only come up with 9 colors offered, unless there were actually 2 different "shades" of red, and 2 different greys.
Maybe 6 roadsters, and 6 coupes per calendar.
If you plan on doing 3 different styles of Calendars (like you did last year) instead of just the the top 12 photos, why not the top 36 entered? That way more forum members can get their cars published.
Of course this all depends on you receiving at least 36 good quality photos.