Put one in a '28 Briggs Fordor and did not get one wrinkle. Used carpet tacks and started at the rear and worked forward. Do one section at a time and work from the middle of the top rail that was working on down to the sides. Do not tack down completely just enough to hold until you pull all the wrinkes out. When it looks good then tack down completely. Took days to get it in so take your time.
I agree with Ed, don't bother now, as you will get new wrinkles after it is installed. A water mist followed by a hair dryer will tighten things up. Not only material wrinkles, but loose spots in the installation. This will work with any cotton or wool liners.