Texturing the Exterior and Interior of a Vehicle

theonewhoknocks

I'm working on texturing a vehicle, and the game it's for will allow the player to enter and exit the vehicle, thus needing both textured. I've been trying to look for models that have both the interior and exterior textured with maps for reference, but I cant find any. A lot of vehicle models also just dirty or lower transparency on the glass to make it difficult to see the interior, to make up for not modeling or texturing it.

I just want to know if its common to use two texture maps for vehicles when modeling both the interior and exterior.