The 4Runner was redesigned for 2010.
There continue to be 2 versions – a 5 seater and a 7 seater. The 7 seater has a 3rd row with two additional seats. The 2nd row bench is different in the two versions – even though both have three seats in the 2nd row.
The 5 seater version continues to be arranged more favorably for getting 3-across, as 2C is wider in the 5 seater version than in the 7 seater version. One obstacle starting with the 2010 redesign is that the seat belt buckle for 2C is longer than the other buckles and seems to be anchored higher in the seat crease than would be ideal – this may make it harder to get a car seat securely installed, and may put the lap belt on the belly (a dangerous place for a lap belt) for an older child or adult riding in this center seat.
The 7 seater version has no tether anchors or lower anchors for the 3rd row – making it only suitable for boosters & adults (although it is itsy bitsy, so not likely to fit anyone well).
2C is narrower in this version than in the 5 seater version. A car seat installed in 2C will almost certainly overhang into 2P enough that 2P can not slide to access the 3rd row.
2003 was a big redesign for the 4Runner – 2C gains both a shoulder belt and a head restraint, and 2D & 2P gain lower anchors.
In 2004, a 7 seater version was introduced (prior to this it was only available as a 5 seater). The 7 seater has a 3rd row with two additional seats. The 2nd row bench is different in the two versions – even though both have three seats in the 2nd row.
The lower anchors for 2D are overlapped into 2C making it such that a car seat installed with LATCH in 2D will block the use of 2C for anything else (car seat, booster or adult). The lower anchors for 2D are also on a hump in the vehicle in a way that will prevent getting a secure installation for a car seat there. Also, it is not possible to LATCH in a booster in 2D as the booster will sit on the buckle for 2D. The only functional position with lower anchors is the 2nd row passenger seat.
2001 was the first year that tether anchors were factory installed (lower anchors won’t come until 2003 in this vehicle). Otherwise, the back seat is unchanged from the 2000.
1991 was the first year that head restraints were introduced for 2D & 2P. The seat belt buckles for all 3 seats are on a fairly long piece of webbing – you may need to twist the buckle up to 3 full revolutions to shorten it in order to get a car seat tightly installed. 2C continues to have only a lap belt and no head restraint – while 2D & 2P have head restraints (that are adjustable & removable) and shoulder belts. Tether anchors may be able to be retrofitted – see here for a $5 retrofit program for Toyota/Lexus. There is a 50/50 split down the center seat.