It doesn't have rear seats and we all know that. My question is if rear seat belts can be installed after I get the car, just in case I decide to take passengers if the situation should arise.
You will need to get the rear seats and belts, otherwise the seat occupants would not be positioned correctly for the belts to work properly, also you will need the rear carpet pieces from a 997.
And in the UK, the car is only homologated as a 2-seater - and cannot be converted to carry more; I don't know what similar regulations you have in the USA.
I have done a rear seat conversion on a 996 GT3. The process was alot more involved than it originally appeared. Required some welding on the rear frame rails for proper seatbelt anchors. $6500 later...I wouldn't do it again.