Here's a good upgrade for those with 4x4 pigs ( or street cars if you really want ).
Extend the windscreen washer hoses ( aquarium air filter hose is about the right size ) under the vents and out the same hole as the wiper. Then run them up the wiper cabletying them down. Use plastic 90 deg water spray ends ( from those cheap home irrigation kits about 50c ea ). Aim them so they spray vertically and hit as much of the window as possible.
Total cost is less than $5 and makes a huge difference to washing the windscreen after some mudwork.
