I'm sure you might be able to make one work on the back of the LR4, I have seen them on other SUVs. The big problem with them on the LR$ is the double hatch/tailgate. Once you put the bike rack on there, you have completly lost all access to the rear of the truck unless you take the whole thing off.
Another concern I would think about is how low the bikes will sit on the rack. The LR4s rear bumper (lowest resting place of the bike rack) is fairl low. Once you get the bikes on the rack, the bike tires may scrape the gound with drive way transitions and such.
I have one of those hitch mounted cargo haulers for when we go on vacation and it will scrape the ground when leaving driveways and even leaving some gas stations with steep transitions to the road. I'm not saying you will have that type of issue, but it is something you may want to think about with one of the racks you are looking at.
I have a Thule T2 rack that is hitch mounted. I would say it is one of the easiest racks to work with for bikes. I have never had a problem scraping it on the ground. For access, I can lower the rack even when bikes are on it and still get intot he back of my LR4. I have a fairly expensive bike (Specialized Carbon S-Works Stumpjumper FSR) and I dind't mind spending money on a good rack and the hitch needed. Here is a picture:
Rob
