Generally, the merchant is not required to collect and pay sales tax from you if the vehicle is purchased for delivery and use in another state or out of the country.
The problem involves use: The term use means any use as a result of ownership. Storage and transporting are considered use of a vehicle. So, a car dealership can and often do charge sales tax on the purchase of a vehicle that is going to leave the premises under the ownership of a person.
The only way to do it other wise is if the dealer ship will do up the paperwork in such a way to indicate the vehicle is being shipped out of the country, with you as the shipper.
ELSE, the vehicle has to be shipped by the dealer directly.