Note: While the Outback is traditionally thought of as a wagon, it was also available as a sedan as well from 2000-2007. If you are looking for the Outback wagon, click here.
For 2005, the buckles for 2D & 2P got much shorter and are now mostly rigid – but 2C remains flexible and on a long seat belt webbing stalk. For 2C, you will almost certainly find the need to twist the buckle stalk (up to 3 full revolutions) to shorten it in order to get many car seats installed tightly – as shown here.
The head restraints for all 3 seats protrude forward and will need to be removed when installing a forward-facing car seat or high back booster.
For 2007, the lower anchors were encased behind a plastic trap door – this can affect installation as it sometimes forces the lower anchor connectors (the hook on the car seat’s lower anchor strap) in a more horizontal position than it wants to be – and doesn’t allow the strap to orient itself vertically as it typically needs to allow the car seat to get tight.
New for 2001, the Outback sedan gains lower anchors (LATCH) for 2D & 2P. Otherwise the back seat is identical to the 2000. 
The Outback sedan was first introduced in 2000. It had shoulder belts AND adjustable, removable head restraints for all 3 seats in back (it was very progressive!), as well as tether anchors for all 3 seats.
The seat belt buckles for all 3 seats are on VERY long pieces of seat belt webbing – you will almost certainly find the need to twist the buckle stalk (up to 3 full revolutions) to shorten it in order to get many car seats installed tightly – as shown here.
