You can drive on a Thai licence supported by IDP it only costs 500thb but you have to go to the LTA in Chonburi with your licence, two photos and your passport. It is valid for two years.
If you dont get the IDP and have an accident, it can invalidate the insurance.
BS detector working here A Thai plastic photo licence is only valid for 5 years and is almost indistructable, so how can it be "a bit old and faded".?