Well, I can tell you what two of them say, but I can't quite read the middle two either. I could have sworn we got a better pic of just the plates, but I couldn't find it.

Mine is the minivan on the left which says "SAX MCHN"
ClemsonJeep's is the Jeep on the right which says, not suprisingly, "CLEM TGR"

The middle two were husband/wife cars. One had a Mark1, the other a Mark2, but can't remember which. I can't quite read them, though.

Sadly, the rest of the people at that meet don't seem to post here anymore (not to my knowledge, at least). That's why I hope I can make it to a big meet some day! I've got to meet some more of you!