Motor vehicle sales tax rates differ greatly inside the United Tells. Car tax by state often varies within counties and municipalities. If you are moving to another state, calculating car tax prior to moving will be useful in determining where and when to decide to purchase. However, if you are trying avoid the car tax from your own home address, go ahead and buying a house to park your car in because unless you have a house or are in the state in question you risk tax evasion. Car dealers and l...