Not sure about Rainx 2in1, but maybe my experience with the original will help you. If you follow the directions and apply regularly, this stuff is a miracle worker. (I went for months with broken windshield wipers and could see well when others were pulling off the road because of heavy rain.) If you don't keep up with it (i.e. apply regularly), it makes it extremely hard to see. Not sure what happened in your case.

From a story my dad told (and I'm not sure which forum that goes in (-: ), I'm pretty sure ammonia will clean off the rainx.

I second the ammonia to remove what's on your windshield. Re-apply the RainX,follow the directions, don't apply a thick coat. I've used regular RainX and it works great for me! Water just beads up and runs off in the wind as you drive.

I love RainX.. but have streaked with it applying in full florida sun. Put it in the shade, open the windows & apply it again once it cools off some fixes it.