I also found this out when looking at a 180 day french visa for ourselves.
A non uk resident can also get 180 days
insurance from a uk insurer. They just go outside the shengen zone for a length of time that I can't remember then renew the 180 day uk
insurance and spend another 180 in the eu and uk.
If they want to ship one back to Australia....sea-bridge.de are about the best to use. They also have a office in the uk .
The build quality of motorhomes got a lot better after 2012.. not many manufacturers get serious damp problems from. 2012...though there are exceptions. Most with window or door installations.