If you see Csharp’s image below the “ledge” is off the windows over the wheel well. The back window was open but the tailgate wasn’t so the best measurement he could get was from ledge to ledge. Might be a bit narrower when taking into account wheel wells.
Hey all, went to the Chicago Auto Show yesterday just to check out the R2. Of course it was behind the golden cords, but one of the "supervisors" was nice enough to take some interior measurements for me. I have dogs (lots of them) and wanted to make sure my crate/containment setup would work...