I just bought a used Charmac 2 horse gooseneck slant load with drop down windows.  The windows have grills and sliders that open part way (bus).   The problem is the grills are attached to the drop down window, so when you open the window, it's a big open space, which I don't really like... my horse will one day take that for the exit, and I see a train wreck coming.  I have a few choices:  have a few bars welded to create a permanent grill (a guy at my barn is a welder), use small link chain covered with rubber to create something like a stallguard, use the big window screens to cover the window opening (doesn't seem safe enough without the bars or chains).  What would you all suggest based on your experience?  The window opening is really big;  I am 5'7, 150 lbs and I an easily get in and out of the opening.  Any other ideas are welcome :)