Nick - that's a good plan.
Insurance companies will walk away if they see any loop hole or grey area. It's their easy get out clause. So it must be ironclad. But this only gets tested when the smelly stuff hits the fan and the fan is on high. Then it all gets unpleasant
In the EU at present we have Type Approval. It's the guidance for all sorts of things, like safety testing; and it's the limit of liability 'get out clause' for the manufacturers. In the UK the 7 seater D2 only comes with type approval for air springs on the rear - unless it was modified by SVO (long story). If we ran the zero mods rule that the Spanish use, then any mods to that wouldn't pass the MoT. Suspension changes here in the UK are a major issue with the DVSA and are part of the points system. As that specific vehicle came only in that form, then any change must be notified to the DVSA (with each all the various legal interpretations that involves). You can change the spec of the vehicle to 5 seater - but this must be done via the DVLA.
It's interesting to see how many after market spring retailers mention 'not for road use' on their non standard springs
As I mentioned before
"I've based my opinion on type approval regs. An MoT isn't a legal vehicle approval check - it's a mandatory vehicle safety check built around a finite list of checks; so has nothing to do with this. Small print on ALL vehicle insurance places the blame for a non legally compliant vehicle at the door of the person who holds the insurance.
I've run this past Bristol DVSA, Somerset and Avon CIT (as was, thinks its now CSI), Exeter VOSA (as was) and one or two others.
No one gives a damn until their is a crash - then they give a damn
I base my interpretation of the law on advice, guidance and primarily the need to cover my professional arse"
I may not make a living out of vehicle prep, but it's part of my income. I have a good reputation. Added to which I have a duty of care - this goes beyond my TPL and Professional Indemnity Insurance. So I'm happy.