I am on the fince about this. My rear defroster grid is shot beyond repair (too many gaps in it) the only way to fix it would be to replace the rear glass. What would you do? Replace the glass first and then tint, or just tint over the broken grid?
Well, do you use the defroster? If so, I think I'd want to be able to use it. There are kits (conductive paint) that allow you to touch-up the grid. A tint/glass shop could fix yours (and do it well) for a lot less than new glass, don't ya think?
I have a hatchback car with no rear defroster. It really friggin sucks. I used something similar to CPU fans in the corner of the rear-window to blow air across the glass (powered by the defroster). Otherwise, I was screwed on cold mornings. Just in case that sways ya towards fixin it.