Mud Flaps - How Effective?

[Syncopator]

Dutring this recent nasty weather I get a lot of filthy water along the sills below the doors and on the rear, below the number plate.

Do their mud flaps reduce this significantly?

I also notice that every time it has rained while the car is parked overnight, there are vertical black streaks from the four drain holes along both front doors' bottom edges, on the sills below the doors.

What the hell is inside the doors to produce that? And will it clear up in time?

[Uncle Bob]

Mudflaps make Sence on the front, keeps a small amount of road dirt off the sills, waste of time on the back due to very short overhang.

[FROSTYBALLS]

When I had my 2006 Corolla, mudflaps wouldn't fit due to the body kit. The rear window and tailgate used to get plastered in dirt.

Had mudflaps fitted to both my Auris, and nowhere near the same issues.

[MikeSh]

I also notice that every time it has rained while the car is parked overnight, there are vertical black streaks from the four drain holes along both front doors' bottom edges, on the sills below the doors.

What the hell is inside the doors to produce that? And will it clear up in time?

I believe most modern cars are built so the rubber 'blade' on the outside doesn't actually touch the glass, so water will run down the inside of the door - hence the drain holes.

I think the logic is that water will get in anyway - it's very hard to make a moving seal in that sort of situation watertight - and having a gap means grit doesn't get trapped and scratch the glass. That's either my hypothesis or I read it somewhere - can't remember which though .

[Syncopator]

But why is the water which travels through the doors' innards so filthy? It really is very noticeable and gives the impression that there's something being flushed out.

[FROSTYBALLS]

We've had 17 cars from new, and have occasionally had this black streaking effect. It stops after a while.

[Syncopator]

Thank you Mike, that's good to know.

And I think I shall invest in front mud flaps to reduce the spray which lands there when in motion.

[Uncle Bob]

Here you go,genuine front mudflaps from a dealer.....

http://www.ebay.co.uk/itm/TOYOTA-AYGO-FRONT-MUDFLAPS-GENUINE-TOYOTA-ACCESSORY-/130659612848?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item1e6beb78b0

[Parts-King]

Despite there being a rubber scraper seal on the door frame / glass, it is not intended to stop water. The seal is there to stop all the crud getting into the door and damaging the glass. Does anybody remember RA/TA 40 shaped Celica's back in the day? They had no door frame as such and the glass ran up and down a roller, within a short space of time they made a right mess of the door glass, scoring lines into glass and making a right mess

So in short, the door lets water enter in (thats why you have a membrane inside to stop water wetting the door card) but there are drain holes in the bottom of the door to let water out, the door is not going to corrode. I think the black is off the rubber, take a clean damp cloth to a wiper blade and see how much black comes off the rubber, you would be surprised

Kingo