If use Rain-X will get watermarks...prodigy said:First thing you should do, DO NOT use Rain-X.
From my previous experience, Rain X is the main culprit that causes watermarks. I had a similar problem too, but i just stopped using it and after many many car washes over a period of time, it just goes off.
Alternatively, you could use those soap powder. Fab of something that is strong enough and wash the windscreen, it'll help abit. Again, you must wash it a couple of time before it slowly wears off.
You could use something stronger like alcohol/thinner to remove but you must be very very careful not to put too much coz you might end up scrubbing off your car paint instead.
If not use Rain-X difficult to see during rainning.
Really in dilemma..
Anybody, have any alternative................