Joel907, might be a hard pill to swallow, but how about not running your dog in HT for a while? He's only 15 months, about the only thing you're going to accomplish is making the problem worse. Being able to do the work isn't the only criteria. Being mature and stable enough not to lose their heads is also a good idea. You're setting yourself up for a lifelong problem with your pup if you're already looking for bandaid solutions to manners. Stop running and train your dog, run fewer tests, build that standard in him. I know it's fun to brag about how young your dog got titles and passes, I totally get wanting to run your dog, it's fun, but it really isn't worth it if it sets your dog back in the big picture. Unless SH is your end goal. Also would recommend Dennis Voigt's TRA dvd, he's got some nice ideas for pre-test routines. Train your dog vs just airing/running to get the energy off. Get to the test area early, find a field and train.
Whatever else you do, you need to get his attitude and head in the right place, from the instant you are getting him out of your truck, he should be in your world before you ever get to that holding blind. He's not the one calling the shots, you are, and if he's wild getting out of the truck, getting to the blind, leaving the blind, walking to the line, at the line, then address that. It is impossible to replicate test atmosphere in training, but, unless your dog is wired wrong, you can go a long way in addressing many of these issues in everyday training, especially if you can find someone really good to watch and help you and make suggestions as to how you can modify what you are doing now. Read the dog, it isn't about blunt force necessarily, whipping or burning some manners into a dog, as much as it is getting the dog in the right mental state, to be in tune with you and listen to you, be in your world on your terms, not his, while maintaining a good, confident attitude to do the work in the field. I hate seeing a beaten, slinking dog as much as I dislike having a wild out of control one. It is simple, but it isn't easy, this whole balance thing, keeping the total picture in mind, but the results are worth the effort. When I think about how bad it was with my first HT dogs, how much I dreaded, hated, feared, holding blinds, getting to the line, it really clouded the enjoyment of running my dogs. But, think about it, take a look at the photos of the Nationals and National Amateurs for instance, those dogs are sitting, standing or laying in the holding blinds with their handlers, not zonkers (of course there are exceptions but, in general). To be at the top of your game, whatever the venue, has to start back at the truck first.