They discuss this in the Top Gear Bond episode with Hammond. Check out around 48 minutes:

I just picked up a clean 2007 RL for $12k with less than 75k miles on the clock. It runs like a dream, will unlock the doors for you when you touch the handle, and has keyless start. SH-AWD is great at handling the weight as long as you accelerate through the corner and let it work. The 0-60 is just under 7 seconds…