I have 2 dozen ATV's running around the Western US, 2 per flatbed trailer. The field crews that use these ATV's stay in motels. All we do is run a length of chain through the ATV frames and around the trailer steel sides then use a lock to secure the chain.
In the past 15 years the only ATV that has been stolen was in Tucson AZ and it appears that the crew forgot to chain this one up. Its running mate was still on the trailer chained up.
We leave ATV tire repair and emergency stuff in the soft bags setting on the ATV's and have never had anyone mess with that stuff. Some times the trailer with bikes is left in the motel parking lot with just a tongue lock attached and no one has ever drug off a complete trailer set.