I noticed this year there where a LOT of two cars per site. Granted a few where able to tuck in tight, but most had a car sitting right on the "line" of the loop and it definitely made the loop road pretty tight for any big rig.
The public website even states under parking, officially there is room for 1 vehicle at the campsite. If you must have 2 there, then be pilot and try not to make the loop road hard to drive past your site.