Last month we exposed you to the world of automotive plumbing. We covered everything from what the heck "AN" means to what material hose might work best for your particular application. We discussed the differences between AN threads and NPT ones. We even mentioned the importance of using 37-degree flare, automotive-specific fittings, and not 45-degree, home improvement store brass ones. Of course, theory's only good for so much and whether or not you can actually assemble a hose yourself can make or break an otherwise on-time project.