Any Thule product that mounts on their "Rapid Tracker" bars will also fit in the cross bars of the LR Expedition Rack. I mount four Thule 599xtr Big Mouth bike racks on my Expedition rack. Make sure you buy the additional adapters that allow that bike carrier to mount to the Rapid Tracker bars. The carriers come with the mounts for the older square bars. The Rapid Tracker system uses T-bolts that fit perfectly in the Expo Rack cross bars. I bought the whole set-up through REI in February when they had a 20% off sale on all Thule products
I stagger the bikes forward-backward-forward-backward. To get them up there, I stand on the tire and have someone hand me a bike. Easy to do with a road bike, not so easy with a 35 pound down hill rig.
This past spring I bought one of those off-road pop-up campers, mine is a Starcraft but Fleetwood makes a similar unit, I mounted the Rapid Tracker bars on the roof of the camper with the recommended Thule mounts and I can easily take the bike carriers off of the Rapid Tracker bars and put them on the LR3. The reason for the swap is the LR3 with the bikes on top needs something like...14 feet of clearance. We drive to our camp site with the bikes on the camper and then will switch the carriers over to the LR3 for the drive to the trail head. One of these days I'll post pictures of the WHOLE rig: '05 HSE, Expo Rack, Raised Air Intake, LR driving Lamps, Rear ladder, 4 Pelican caes fitted into the Rack filled with climbing and backpacking gear followed by the camper (if ever a pop-up camper could be called Bad-#**, this camper is it) with either four MTB's or two MTB's and two kayaks.
I'll admit it, I'm a gear freak.