If I were you I would tell her she is buying an "orphan" as the R-Class is no longer marketed/sold in the US. Most people do not want to buy vehicles that are phased out.

The Mercedes dealership that I do business with does not resell any of the R-Class vehicles that are traded in as, they can be very expensive to maintain. Every one is wholesaled out to other used car dealers. That should tell you something. In addition, when the service department warns you of this before you spend big bucks to maintain your future business, I listened and moved on to other Mercedes vehicles. I was very grateful of their honesty. Not many dealerships would tell you this when they could make money servicing something that is a "money-pit."

If money is "no object" to your wife, you may want to ask her if she wants the hassle of taking the vehicle in for repairs.

If none of this makes any sense to her, all I can say is she has been forewarned.