Any extra fees when buying a car can be a pain. Registration fees, stamp duty, and insurance can add hundreds to the purchase price. But do you have to pay GST on a used car?There are a plethora of fees involved with buying a car, even if it is used. There is the initial cost of the car, the stamp duty you pay when you transfer the registration into your name, insurance costs, and all of the running costs.RELATED: How to avoid the luxury car tax in AustraliaGST is one of the extra fees you must