I asked my dealer about this and he said he was not aware of the problem on any Plus Six they have sold.
It could be that only the early production run cars have the dropping suspension problem. Or may be it is a matter of age and mileage - we do tour a lot in our cars as NZ is a bigger and much longer country than the UK.
See what you can find out about when the cars your dealer has sold were made. All our four Plus Four cars were made late 2019, however our NZ dealer has a new 2022 Plus Six and we are going to see if it is possible to check the ground clearances on this car.
