Motor vehicle sales tax rates differ greatly within the United Levels. Car tax by state often varies within counties and towns. If you are moving to another state, calculating car tax prior to moving possibly be useful in determining where and when to buy. However, if you are trying avert the car tax in your home address, go ahead and buying a house to park your car in because unless you keep a house or live in the state in question you risk tax evasion. Car dealers and native motor vehicle regi...