Windshield wipers rain system.

Hello. I want to add rain drops on windows of my car. I want to use texture with changing offset to make simple animation of the drops. But the problem is in windshield, how could i make this effect on animated texture, when my wipers are ON? Make some parts of the texture invisible (i posted an image).

[78889-безымянныи.png|78889]

Is it possible, or is there any other solutions?

Rain FX Pack - Cloud and Hail Weather VFX