My friend Bill Clark (Roundhouse Bill) sent me some photos he took at York displaying the new S Scale Auto carriers and Billboard reefers.
It appears Lionel chose to use the same truck mounting screw hole that was used for the O gauge trucks. It also appears that the truck has a truck mounted coupler with an extra long arm. The cars should negotiate r20 track without any trouble. I would expect some overhang of the ends of the cars though on r20 curves. It's too bad Lionel has chosen to use the one piece molded plastic ladders like those used on the early O gauge cars. Later version Die-cast metal ladders would have been a better looking choice IMO.
The Billboard reefer car looks pretty good. I can't tell if the ladders are molded on or add-on pieces. The detail does look good although nothing can beat an SHS or MTH billboard reefer for exquisite detail.
The cars look to have release dates of July (reefer) and August (Auto Carrier).
Mark