Just bought a '08 Suburban LT. It did not come with a cargo cover...the cover that slides over the very rear cargo area. Does this item come with the vehicle? I don't recall seeing a cover on any of the other Suburbans on the lot, but have seen mention of it on the web. Also, if it is not included...where can you get one...I looked on Chevy's website and did not see it listed as an accessory.