mickm, there is a simple solution. If you cannot do it yourself, get an auto sparky to install a switch connected to the fuel pump. When you want to be away from your rig, turn the pump off. You'll find most car thieves are opportunistic and will leave you alone and move onto an easier target. Make sure the switch is in strategic location.
Larry

Turn the key off, remove said key from ignition switch this will mostly engage a steering lock and disable the fuel system by operating a fuel shut off valve, jump out and lock the doors (this will more than likely operate a anti theft device). Now go away and enjoy yourself without the paranoa of some one stealing the MH. In all honesty if they are going to take it they will, like if they have a sale for your type of vehicle they will just drag it onto a tow vehicle and take it anyway. Make sure you have good insurance and by locking the vehicle you have done all you can
cheers
blaze

Depends on how it operates a switch that leaves on - off. Solenoid in off position so its doesn't activate with key..
I would like to see you take a coil lead off or rotor out of a modern petrol engine ! Lol

I'd be just as or more concerned about my vehicle being damaged. The chances of a person out to steal a motorhome stumbling across yours in a remote location are slim therefore need to be more concerned about opportunistic thief or curious people. they could easily do many hundreds of dollars damage just trying to get in to have a look. This would worry me in a remote location especially if i was leaving overnight. We have left ours on occasion but always at a campsite where others were staying until we got back or in a busy place with lots of people around.