As far as State Sales Tax is concerned, it is impossible to list definitive criteria, as each individual state views both rates and liability differently. As a general rule you should expect to pay some form of tax when registering your vehicle in the US. However, as a military person, you may qualify for exemption if the vehicle has already been bought and owned out of state (sometimes for a specified time period); this may also fulfill the criteria for exemption. It's always wise to try to obtain first-hand information from the appropriate local office. For an overview of the various State rates click here then navigate to the relevant section.
Neither the Military Sales Program, nor its representatives will be responsible for any form of tax liability on automobiles imported into the USA. As is universally the case, tax liability rests with the individual and ignorance of the appropriate legislation will not be considered as grounds for exemption.