From what I understand, the problem of using any professional tracking system is as soon as you notify the company that your caravan/ Moho has been stolen, they remove any chance of you tracking it (so that you don't follow it and get into any potential conflict). By the time they have alerted their own recovery team to try and recover it, you probably won't want it back anyway.
You can put your own micro tracker in the van and secure it discreetly. They cost about £25 and have a 6 months battery life and are accurate to about 50ft.
Most good people would recommend not getting involved with trying to recover the van yourself.
Most bad people would have an alternative opinion.