[ElMagicoR]

AttachObjectToVehicle(objectid, vehicleid, Float:fOffsetX, Float:fOffsetY, Float:fOffsetZ, Float:fRotX, Float:fRotY, Float:RotZ);
objectid - The object you want to attach
vehicleid - The vehicle you want to attach the object to
Float:fOffsetX - The distance between the vehicle, and the object (X direction)
Float:fOffsetY - The distance between the vehicle, and the object (Y direction)
Float:fOffsetZ - The distance between the vehicle, and the object (Z direction)
Float:fRotX - The X rotation between the object and the vehicle
Float:fRotY - The Y rotation between the object and the vehicle
Float:RotZ - The Z rotation between the object and the vehicle