The VehicleTypeEnum enumeration contains 'caravan', and that's it.
First of all it is not clear to me, whether this includes only the trailer species or also the things that have an engine themself (I call it a 'motorhome' but as I am a non-native speaker this might be AE ir inadequate, or both).
Whatever the language clarification reveals, the current enumeration does not allow a distinction between trailers and vehicles, which I was told is required for proper modelling of parking facilities.
Hence I propose to ad a literal 'motorhome' - plus clarification in the definition tagged value.
The UK Department for Transport uses the term "Motor Caravan" with an image clearly showing an integrated motorised vehicle with built-in accommodation.
I see this issue was resolved by promotion of the Parking extension to the core model, since Parking included motorhome.