Hey Matt,
Here is my .02 pennies, I understand your unhappiness with how the judging went as it can be very frustrating as there seems to always be something about the judging at all contests that someone disagrees with. I am a judge at an IPMS event and also did a stint as the head judge at the same event. That being said most IPMS events have judges sign in sheet for folks to volunteer to judge, here is what I have suggested to some that have had issues with how the judging went, basically if you enter in more than one catagory maybe not enter one or two catagories and volunteer to help judge those catagories and that way share your knowledge of the subject(s) so as to make better judges out of everyone concerned and who knows you may learn something too!! especially if you also help out with say aircraft, armor or what ever. As an aside by being a judge with automotive knowledge you can also point out models that have been place in the wrong catagory. Also please note that IPMS contest rules are based upon fit and finish foremost.
Hopefully this helps to ease some of the pain, and like I said its just my .02 pennies!