I think a couple of year ago, Lincoln would have been in the running when the Navigator was popular. A lot of people complain about rap and all, but they do help promote sales. But that only lasted awhile.
Cadillac probably has the better youthful market right now. Escalades forget about it. You either have little rich white boys, black kids a work for it, you have the people that have stolen it from the older people, and of course the middle aged mother who loves SUV's (this is where the SRX will fit in also, but it will not do as well in the long run as the Escalade and faimlytwins).
The CTS along with the LS are a mixture of young and old consumers. Just from my experience on the street, the LS is driven by both young and old. The younger buyers most likely have purchased a 2000-2002 used LS which is a good thing to do at a younger age. Since the CTS is new, most buyers are 30+ with again a mixture of younger (around 30ish) and old.
The XLR will also appeal to the middle-aged ("LIFE CRISIS?" - I am making a new thread about that

) who has some money, and waht a nice raodster to cruise or mess around with.
Now, the large sedans, forget about it. Those are geared toward the older drivers.
But in my opinion, as of right now, Cadillac has more appeal to the younger people than Lincoln. Lincoln is slowy making its way up with the younger buyers (or hand-me-downs of the LS like me) and also some of there concepts like the mark 10, (ford thunderbird), the mark lt (ford f150) etc.