i would hit it with a hammer or something and call my insurance company and have them replace it (i get free glass). thats the only way your going to get it fixed the right way.
get on top of it quick. My car had that problem before I bought it and has rusted out area below rear glass on shelf area. Have a glass a glass company pull glass and reseal it.
Hi,
I agree;you have rust issues. My '83 is not totally gone, but has issues along the front of the trunk sealing area. That's not far from your rear window area. I can extrapolate the additional damage. God damn the rust monster!