Your profile says you are from San Diego. I suspect that the salt air around there contributes to this, too. Think about it. Why would things be any different on an island in the Pacific Ocean?
I question the whole idea of shipping a car to Japan in the first place. Why is this such a fixation in your mind? If you think you're going to enjoy driving it around a new country for 5-7 years, you should determine just how often you will have a chance to get out and what the driving options will be wherever you are stationed. My advice is to sell this admitted rustbucket and save yourself a heap of money before you return to the States, at which time you can enjoy another car in a land where people drive on the side of the road that you are used to, where road sign language is not confusing, where road tolls are not so expensive, where speed limits are higher, and where any accidents can be discussed in a language you understand.