i've seen the repair description. looks like a pain in ##. can you scrape it off and put on an aftermarket? where the best place to find replacement?

if you only have a couple broken lines, it's really not that hard to find the break and fix it. Just run a voltage meter/test light down each line until the voltage changes from 12v->0v (or vice-versa).

 

I have no idea if they make aftermarket rear defrost grids; I'm guessing not.

Probably the best bet would be to find a replacement back glass with the defroster lines intact. Would save the trouble of repairing those damn things.