I have an Outcast Pontoon boat that a "friend" dragged down the road upside down that broke the zipper car. It was actually a pretty easy fix once I found the right sized Zipper Car at Sailright. It was $1.30 plus shipping, part number 120863 a Size #10.
My zipper was also damaged, so I had to sew it partially shut where it was damaged near the tip, but it's perfectly functional, albeit a little uglier than it used to be. Good Luck!