Here's a bit on 3rd row safety: (not specific to the LC)
"In addition, a child seated in the third row is not necessarily safer in a frontal collision than a child in the second row. A 2005 study by Transport Canada (the Canadian equivalent of the NHTSA) showed that youngsters are likely to face the same forces in a frontal collision regardless of whether they are seated in the second or third row of the vehicle. The study, which involved a crash test dummy representing a 6-year-old seated in a booster seat in the second and third rows, found equally elevated forces in both rows.
Plus, third-row occupants are at greater risk than second-row occupants in rear-end and side-impact collisions, because they're closer to the rear of the vehicle in a rear impact and are even less likely to have side airbags to protect them. Currently, only about 55 percent of vehicles with third-row seating have side airbags that cover all three rows. And bear in mind that even if your vehicle does have three-row side curtain airbags, they may not extend down far enough to protect children. (For more on this topic, see our article, "Who Benefits From Side and Head Airbags?")
Third-row occupants are also vulnerable to flaws in the seatback's design when they're involved in rear-end collisions. Many seatbacks are either too rigid, which can cause whiplash, or too yielding, which can cause the seat to partially or fully collapse, allowing the occupant's head to contact the rear window, liftgate or even an intruding vehicle in a severe crash. This is particularly a concern in small and midsize SUVs, where the third-row seatback is usually much closer to the rear window than in full-size SUVs. In an informal survey of vehicles with three rows, distances between the third row and the rear window ranged from 8 to 33 inches, with the smaller SUVs generally having the shortest distances.
Is 8 inches or even 1 foot enough space? It depends not only on the strength of the seatback, but on the other safety features built into the vehicle. When Toyota, for example, added an optional third row to the Highlander midsize SUV, it included extra bracing around the rear door opening, along both sides of the cargo bay and up over the rear wheels to help channel the energy away from occupants during a crash.
Volvo considers 12 inches the minimum safe distance between the head of a third-row occupant and the back of the vehicle, according to company spokesperson Dan Johnston. Even with that amount of space, the company has reinforced the rear and tailgate of its XC90 midsize SUV with boron and ultrahigh-strength steel to reduce the possibility of intrusion into the passenger space."
http://www.edmunds.com/car-safety/how-safe-are-rear-seat-passengers.html
