My secret to perfect wrinkle finish painting is to follow the directions EXACTLY.
3 coats 10 minutes apart. Start on a sunny day, put the dash on something you can carry out into the sun, a board or something like that.
Paint it 3 coats in the garage to keep the bugs, dust, and leaves off it.
5 minutes or so after the last coat, put it out in the direct sunlight and it will wrinkle up in about 10 minutes.
Now bring it in the garage, do not touch it as it takes a day to fully cure.
I would pick a warm day to do this, not 70 or so but at least 45* or so.
I have done it in the winter and it works fine, just not sure about 15* even if it's sunny.