@Von Jones OK, I finally got this thought out for the easiest way and a nice looking way to make this a sturdy cart. All you will need is to saw inside blocks for the legs and GLUE and screw them on. I would say at least 3 wood screws per block. These blocks can be stained so they won't be that noticeable and won't be an eye sore like adding boards to the front. Cheap 1" x 2" should work great. Hope this photo helps. Picture yourself sitting in the cart looking at the inside of the legs. Now picture little tightly fitted blocks, glued and screwed, that will stop this shift.