I used to own a winfshield business for several years... I found that "Aquapel" works better than anything on the market. The label says it's guaranteed to last 6 months. I applied it to my commuter car 7 months ago and it still works! It's not as cheap as rain-x, but lasts like crazy! You can get it on ebay or your local glass guy should have it.
Dano
