Many years ago I tried the regular, concentrated Rain-X treatment. Though I applied it properly it worked for a short while but would then develop smearing. Nowadays I use the orange Rain-X premixed windshield wiper fluid. Every time you use the fluid, you rejuvenate the Rain-X treatment. I get great results when it rains, and I get no smearing, ever.

It has been at least 10 years since I used the original Rain-X, maybe the formulation is better now.