I have a cart like LowNslo's except for I 1 upped him! This proves that it doesn't matter what you have someone will improve on it;). I put a couple of cloth tarp straps one on each and about the width of a bottle that way all my bottles stay standing up. I also use a couple of square Adams detail blocks as bookends to keep them in place as well. I have a ramp that I go up and down when I wash my cars. I use my cart all the time, keeps my Adam's products all in one place and organized.