Used.
I've done pretty extensive looking at this point and it would seem not one single car manufacture has a car that has a back seat wide to fit 3 adults for any period of time. The widest back seat seems to be that of the full size pickups with crew cabs and SUV's based on them. For example the 18 Silverado Crew Cab has 40.5 head room, 40.9 leg room, 65.7 shoulder room, and 60.2 hip room.
Compare that to say a 16 Nissan Altima (our old car). Headroom 37.1, legroom 36.1, shoulder 56.4, hip, 52.1. Most cars and smaller SUV's are around this same size with few exceptions. The edge is a bit bigger, head 39.3, leg 39.6, shoulder 58.7, hip 56.1.
So it would seem to really haul 5 adults in comfort for more than 15 minutes, you have to look at something with 3 rows, or a full size SUV/Pickup.
2017 Thor Hurricane 34J
Gone-2014 Chevy Express 3500
Gone-2016 Jayco White Hawk 32DSBH
Gone-2013 Keystone Bullet 294BHS
Gone-2007 National SurfSide 34DE
Gone-2006 ForestRiver Sunseeker 2900LTD
Gone-1994 Fleetwood PaceArrow
Gone-1978 Kit RoadRanger