The Operator's Guide for a sled equipped with a passenger seat will show you the proper adjustments to safely carry a passenger. Some ski-doo snowmobiles are sold with a single rider seat but can easily accommodate the installation of an accessory passenger seat, while other Ski-Doo snowmobiles come standard with a two-person seating arrangement. One accessory that makes riding 2-up even more fun for a passenger are the heated hand grips with wind deflectors.