8 foot cable around frames and rack and thru hitch's safety chain loop.
Another 8 footer thru the wheels and around the rack, and again, through the safety chain loop.
At work I felt pretty safe with the bike on there, I probably didn't even really need a lock. If I was going somewhere that I did feel there was a chance of some theivery going on, the bike went in the trunk, or inside with me. The cables basically keep the honest people honest. Of course, I'm not sure anyone would go thru much trouble to steal a 9 year old Trek 4900 or a entry level K2 hardtail.