The classic additions cover ive got for my car has been superb, its the outdoor one as occasionally my car is outside for a few months, its amazing how well it lets the car breathe, you can park the car up wet, put the cover on it, it rain on and off for a couple of weeks, and then when you take it off its somehow dry underneath.

As per the other thread though, dont expect it to last more than a year or two if its outside continually.

So are they worth the money in terms of how well they protect your car? YES
Are they worth the money as a very long term storage solution that will last years without replacement? NO