Brian years ago I installed a top on my Falcon Futura. I ended up with wrinkles in both sail panels The problem was (other than I wasn't a upholsterer guy) i installed the top with the thought " when it's on I can take a heat gun and take out the wrinkles'. Didn't happen. It worked ok when I was recovering airplane surfaces but not car tops. the trick I later found out was to heat the top fabric as you installed it. not after. Dacron shrinks top material st reaches. Unfortunately a heat gun wasn't hot enough. You need a steam source. Didn't have one. I learned to live with wrinkled sail panels. Some time life's to short.