What did I do wrong?

[kirkatizer]

I've never had to wipe Rain-X off after application. Neither have I had to use MF towels. I do one or two sprays on a paper towel and wipe over the window. No need to wipe off again as you would be removing the Rain-X itself. Wipe on and let it dry. Use as little as you can to cover the window leaving no residue that won't dry. Hope this helps.

[allenk4]

I have applied Rain-X following the manufacturers instructions below. I only did a basic 2BM wash with plain old car wash soap.

Product Usage Instructions

Clean and dry surfaces before treating

Apply in temperatures above 40 degrees F

Apply Rain‑X® to a small, folded, dry cloth

Wipe onto exterior glass using a firm, circular and overlapping motion

Allow product to dry; a slight haze may appear

Reapply Rain‑X® to ensure complete and uniform coverage

Remove final haze with a dry cloth or by sprinkling water onto the haze and wiping with a paper towel

[allenk4]

I've never had to wipe Rain-X off after application. Neither have I had to use MF towels. I do one or two sprays on a paper towel and wipe over the window. No need to wipe off again as you would be removing the Rain-X itself. Wipe on and let it dry. Use as little as you can to cover the window leaving no residue that won't dry. Hope this helps.

Do not follow the instructions above with Rain-X® Original Glass Treatment - Rain-X

[allenk4]

The windshield has to be crazy clean before you apply any kind of sealant to it. Crazy clean as in the only thing the sealant touches is glass. No residue, condensation, or any other kinds of films can be present. Not to mention the psychrometry outside and on the glass surface must be at permissible levels for the product to work. What were the outside environmental conditions? What about the temperature of the work surface? (Most people don't check this...) Any other variables?

Making it too complicated.

Rain-X is easy

Rain-X® Original Glass Treatment Video from Truck U TV - YouTube