2001 mustang convertible

I have a 2001 mustang convertible that drips water from the fold near the back window. Took it into the shop and they said when water sits in the fold after a number of years it has rotted the fabric. To fix it, requires new fabric which has the rear window attached for about $1000 plus labor. Has anyone had this problem, is there an after market part or a quick fix? Thanks Len