I just had a new top put on mine too about 6 mos ago and having the same trouble. I don't use anything except a towel when folding the top away, not rolling it up though. I only use the towel if I am putting the hard top on and not going to be using the soft top for awhile. The dealership that installed the top says that the creasing is normal. I did notice that the back window is a lot bigger now than it was on the old top. I find one thing that helps is not leaving the car in the sun, expecially with the top down. Also when I get home or to work I put the top up while parked in the garage. The soft top is very sensitive to the sun and extreme cold. Good luck! Enjoy the spring!
Regards,
Brian