I accidentally bought one of these single-use Rain-X things about 4 weeks ago, so I decided to try it. You rip open the packet, rub down your windshield thoroughly with the towelette thing, then buff it off - sort of like waxing a car.
By performing this ritual, I was able to keep it from raining in Texas almost a month. But recently, we've had a couple of rain showers - and today it was
really raining and I noticed a HUGE improvement when driving in the rain. The water beaded up and it was much easier to see.
It is so worth it - especially since it only costs 99 cents. I gave it 4.5 stars vs. 5 stars because it's a bit of a pain to apply, especially for those with gas-guzzling, environment-hating SUV's (i.e. me). I was climbing all over the place trying to reach my entire windshield and it was not lady-like (so Lisa - don't even attempt - just ask Rob to do it for you).
Kate
P.S. A couple people at work told me I was a late adopter for this product and that it's been out for like 20 years but since I didn't know about it (I really don't frequent car parts stores much) I thought yall might not have either.