I purchased a used Escalade roof rack for my 2007 Tahoe. I got two side rails, four end caps, two cross rails and the two alignment "plates". It looks great, except the bottom black plastic base is dinged up. There seem to be three separate pieces on each side, one below the chrome bar and one below each end cap area (Or perhaps mine is supposed to be one piece for each side, and it is just broken into 3 pieces). I can't find part numbers for this base piece . Any help on part numbers would be greatly appreciated.