It is possible for the travellers to enter Iran
through Bazargan border by their private vehicle.
For doing such a thing, the travellers require to
take passing card from the Automobile club in their country.
The following documents are necessary for entring
Iran by private vehicle:
international driver's licence (having enough validity)
International automobile card
Although the passing card you have taken from the
automobile club in your country has 1 year validity,
according to Iran's law it has just 3 month validity, so if you
desire to stay in Iran more than 3 month, you have to pay some
money and extend it in Iran.