I use a similar sunshade like pasusan linked to, only mine was sized to fit a semi-truck, so it's a tad big, but there's plenty of flexibility. I cut reflectix to fit the front side windows (a couple of magnets taped to the cutouts holds them in place); and yes, I use a $25 velcroed-in screen door (Amazon) over the slider. I just trimmed the screen fabric so it was short enough to not get caught in the slider track. A hint: go a little wider than your opening, these screens self-close the best when there's some slack in the fabric.
