I scripted a vehicle and when is is enabled, it won't let the Jeep_Tire.dts file to spawn.
Here is the code:
Add-Ons/Vehicle_Limo/jeep_Tire.cs (0): preload failed for jeepTire: WheeledVehicleTire: Couldn't load shape "Add-Ons/Vehicle_Limo/jeeptire.dts".