Because they don't have any, or don't have "allocation" for very many new ones. The LR4's are selling quite well, so perhaps you should consider ordering one. See what they'll give you off the list price if you "order" one they way you want it. My local AD does not have a lot of LR4's right now either, and the 2011's are coming in slowly. I went there two weeks ago to look at an LR2 to replace my 08 CTS and they only had a couple of used ones for me to drive. They just got their first new 2011 in, but it had not been prepped yet. The two used ones were 2010 service loaners with 8 and 12K miles on them. They didn't even try to sell them to me, they knew I was after a new one. He suggested I order one (and he offered me $2k off list, but I know he'll go more), and said delivery would be Feb. or so. I need a replacement by mid March, so I'm not sure what I'm going to do yet. He only has a couple of LR2's inbound over the next 45 to 60 days, so I may have to order one if I want a new one. I wonder if LR isn't holding back on production, as it seems not many dealers have much inventory. There's another LR dealer about 80 miles from me, and he's wiped out as well.
Cheers,
Joe