This is the 303 I just used on my top:
Amazon.com: 303 (30606) Fabric Guard Trigger Sprayer, 32 fl. oz.: Automotive
It worked very well. I covered all the windows/seals near the fabric top with cut up garbage bags + painters tape. Then I just sprayed it on with a good even coverage per the bottle instructions. The prep work took longest, about 30 minutes, the spraying took 5-10 minutes. When I finished spraying, I just removed the plastic and dried any drips/overspray from glass/rubber surfaces. Then it sat in the sunshine for a couple hours to dry. I ended up using about 1/2 - 2/3 of the bottle.
The results are quite amazing. The first time I washed it after coating I couldn't believe how the water beaded up and ran off. I plan on applying this every year now to protect/preserve the top.