My top plastic window cracked this winter also. Guess there's a window virus running around. I got an estimate from the Porsche dealership to replace the plastic...$1000, ouch. Went down the street to top shop, he's done 3 so far this year...$450, reasonable. While at the Porsche dealership, I asked about the glass window and I was actually speaking to a mechanic who was replacing an issue like mine. When you need to service the engine they actually have to remove the top because the glass window will not clear like the plastic, which adds more cost if you ever need to use a dealer. Food for thought here.
