SAM AirportVehicles is a payware extension for the free SAM base plugin and replaces animated and static default X-Plane airport vehicles with high definition custom objects. Additionally a regional system ensures to draw different types of vehicles and liveries depending on your position. By default 3 different vehicle sets are being provided: North America, Europe and Asia.
Additionally you can create own liveries or even custom objects and integrate them into any airport of your choice. For further information in that regard please check out the Developer Guide.