Not really. I'm sure it doesn't last as long as the original coating, but I haven't really paid any attention. Depends a lot, I'm sure, on local weather, whether it's stored indoors, etc.
FLAPS also sells a spray can that you can just apply if the surface isn't too bad. A fresh coating of that every year might last a long time. But I wound up junking the car I used it on, so I can't really say how long it would last either.