Interesting, thanks for notes.
Carolina Wine Company (aka the Hype Machine) has heavily promoted recent vintages of this. It's one of those "I can't tell you who grwos these grapes, but I'll drop some hints" deals. This was from a CWC mailer on the 2000:
"1.) This comes from the vineyard of Bordeaux's greatest Second Growth, which is in fact an identical, mirror image of its greatest First Growth. ("Like two halves of a buttocks", our English agent says.)
2.) There's never been an official second wine from their vineyard. Until 1996, everything not chosen for the grand vin (often 50% of the production) was simply sold off in bulk. Beginning in 1996, though, the Chateau's owner allowed his brother-in-law to select the top 10% to 15% of this de-classified wine, and bottle it as Terre du Lion.
3.) Terre du Lion therefore part of the grand vin until the moment of bottling. It's grown, made and treated exactly the same. Only at bottling, are the two wines separated. Now, of course, Terre du Lion is less concentrated than the grand vin. That's the basis of the selection."
Ok, so obviously they're talking Leoville Las Cases (indeed, Clos du Marquis isn't officially considered a second). Typical CWC hype, but they do sometimes have nice wines.