Rain-X doesn't seem to last long. Great when first applied then the wipers are not needed unless a downpour. Once the wipers are on a while it deteriorates. I have both concentrate and a top up spray.
I redo the Rain-X when I get gas. BTW: I refill at a 1/2 tank. "Loretta's rules". Seems prudent when I often not sure if there will be a gas station available down the road. At home I just squirt Rain-X and wipe/buff before I leave.
