A suggestion
When I had my dodger canvas replaced a couple of years ago, I had them make a full cover instead of just snap-on covers over the windows. The cost was a push in that it took more material but less labor. With the full cover over the top, front and sides of the dodger, it stays nice and new looking and will last much longer. Replacing the cover in a few years will be much less expensive than re-doing the dodger again.