Check AddStaticVehicle/AddStaticVehicleEx/CreateVehicle, they return an ID to identify the vehicle they created. GetPlayerVehicleID returns the ID given by those functions, not the Model ID. Use GetVehicleModel to get the Model ID.
Well... I see you use CreateDynamicCP from Incognito's Streamer... then you should use CreateDynamicRaceCP and move the script from OnPlayerEnterDynamicCP to OnPlayerEnterDynamicRaceCP.