I don't have a photo to share but I'll try to describe our screen "door." It's very low-tech: Just two square dowels with screen stapled to them. The screen is slightly wider than the door opening. We have a strip of stick-on Velcro attached under the drip guard over the door, so that it doesn't show. The top dowel has Velcro stapled to it. When we want to leave the door open for fresh air, we just hang the screen up by the Velcro.
The bottom of the screen has another dowel to add weight
and hold the screen in place. To go through the doorway, we just pull the screen aside and let it fall
back into place. Even though the screen doesn't cover the opening tightly, we have found that very few bugs manage to find their way around it. When we're ready to close the door, it only takes seconds to remove the screen, roll it up and stow it under the window behind the seat back.
It's a quick, easy & inexpensive solution to the bug problem.