Yeah, it's strange it's not tempered glass. I launched a rock cutting the lawn right thru our old Jayco TT front door glass and after I found out the cost of a replacement, I bought a small sheet of 3/8" frosted Plexi-glass and cut it out the size of the opening and Voila! done. The door was far less heavy after the mod too.
2010 Cedar Creek 5th Wheel 34SATS "The Beast"
2006 Ford F350 Lariat 6.0L Diesel
2003 Harley Heritage Softail "Hogzilla"
1986 Marriage to "Wifey" (patience of a saint)