Thor Motor Coach recommends installing the child safety seat in the forward facing booth dinette position.
For rear-facing child seats and infant carriers, the dinette table can be placed in the "down" position to allow adequate room for the rear facing child seat.
If your motorhome is not equipped with a forward facing booth dinette seat, we recommend that small children that require a child seat not be transported in a motorhome.
This is from the THOR manual and is over the top "cover your a$$".
The post above has it covered. Drive with care and best of luck.