The armrest is located in the center of the rear seat. Pull the armrest down from the seatback to use it.
You will find cup holders on the center armrest.
Hyundai Tucson (LM) 2010-2015 Service Manual: Rear Seat Belt Repair procedures
Replacement
Secondary Seat Belt Relacement
•
When installing the belt, make sure not to damaged the retractor.
1.
Remove the rear seat.
(Refer to Seat & Power Seat - "Rear Seat")
2.
Remove the rear door scuff trim.
(Refer to Interior - "Interior Trim")
...
Hyundai Tucson (LM) 2010-2015 Owners Manual: Before starting
Make sure the hood, the tailgate, and the doors are securely closed and
locked.
Adjust the position of the seat and steering wheel.
Adjust the inside and outside rearview mirrors.
Verify all the lights work.
Fasten your seatbelt. Check that all passengers have fastened their seatbelts. ...