Dig a trench3X3X8 so there truck,s get stuck cover with a tarp add leaves,sticks just to make it look natural .If they have to get a tow outon posted land because of a possible accident or theft is in processmany tow operaters will call the police. My buddy has the same problem in ontario he went a little further by waiting for them to show up and leave there trucks then he popped there back windows out added gas and ran for home . He called 911 for a possible car fire then that also send,s out the law to see what,s up. Not really the way to do it but they were caught.