Aftermarket rear defrosters for toppers?

Looking into the feasibility of installing an aftermarket rear defroster for the back window of my topper. When it's really cold out it glazes over with frost and I can't see out of it. I know it's not going to be a completely conditioned space, just looking for something to help with melting off the frost. Does anyone know of a kit, or any tips to help with this?

Thanks!

 

I'm looking for the same thing. I spent some time on Amazon but they only seem to sell repair kits. A quick-ish google search led me to THIS site. Seems like a good deal. I measured the height and width of my rear glass and entered it. For $60, I might try it.