Will fitting rear mudguards to my Octy estate help to reduce the amount of muck that ends up on the back window? The only car that I have driven which is worse for this trick was a Focus (which seemed to have a magnet for dirt and road spray).

i've got the standard little black flaps that are called mudgaurds on my estate, and the back window still gets filthy at anything over 15mph.

its just a trait of any flat back car i think.

it just means you have to use your rear washer more often, which means more of those annoying dribbles from the washer nozzle after you've finished with it.

No!! :( And that's from someone who's got rear mudflaps already!

Best thing I could advise is either a tiny spoiler at the bottom of the window (apparantly this changes airflow to reduce spray, but no idea if it works) or rain X etc on the rear window.

its all to do with aerodynamics ... not a lot you can do apart from the above post. i dont suppose there are any guarantees though.

A spoiler (lower edge flap type thing, like NASCAR, not the vRS estate window-top style) might work, but I'd want to see wind-tunnel photos if my sole or main motivation was aerodynamics rather than styling.

Try it with some stiff plastic board and some tape, it it reduces tape up to a reasonable speed then give it a shot with a decent one.

Failing that wind tunnel time

i've got the standard little black flaps that are called mudgaurds on my estate, and the back window still gets filthy at anything over 15mph.

its just a trait of any flat back car i think.

it just means you have to use your rear washer more often, which means more of those annoying dribbles from the washer nozzle after you've finished with it.

I already have those useless little black things!

I end up doing a wipe 10 seconds later to remove the little dribbles. My 306 (granted it was a hatch) was much cleaner (apart from the black that came out of the exhaust pipe!)

Rear Mudguards ,,,,, no ,, no ,, no !!!

Rain X you have to purchase! Also a no ,, no.

Try (on a clean rear window) rubbing on neat Fairy Liquid. Let it dry for as long as possible (sun helps, some chance this time of year), polish off with a clean cloth.

Works for me, "suits you sir".

Rear Mudguards ,,,,, no ,, no ,, no !!!

Rain X you have to purchase! Also a no ,, no.

Well mudflaps are standard although don't seem to do much.

Cant really see Rain X helping. Mine is mostly covered in a thick layer of salt that would strip it in the first wipe.

I just live with it and clean the rear window when I can no longer see out of it. As for the rear numberplate at the moment, just about speed camera proof and it gets washed every 2 weeks.

Rear Mudguards ' date=',,,, no ,, no ,, no !!!

Rain X you have to purchase! Also a no ,, no.QUOTE']

Well mudflaps are standard although don't seem to do much.

Cant really see Rain X helping. Mine is mostly covered in a thick layer of salt that would strip it in the first wipe.

I just live with it and clean the rear window when I can no longer see out of it. As for the rear numberplate at the moment, just about speed camera proof and it gets washed every 2 weeks.

I assumed mbames was talking WRC mudflaps!

Just study a typical photo of a WRC half-way through the first damp gravel stage after service, to see how much use rally flaps are (mention of chocolate teapots springs to mind).

Still thinking a suitable lower edge spoiler, or an top edge spoiler that is correctly designed to force air down past the rear screen to reduce spray are the only ways.

At this point you are wanting to get real aerodynamics done before you try it, however if you did this for not too much you would probably sell a few of them, by the sounds of this thread

I think something that forced an air curtain down over the window on an estate (which a vRS estate rear spoiler doesn't do according folks on here) might cause lift.

What's needed is a lower edge spoiler to lower the stagnation point to the base of the window, a similar (vertical height) point to where it is on the hatch.

I think something that forced an air curtain down over the window on an estate (which a vRS estate rear spoiler doesn't do according folks on here) might cause lift.

What's needed is a lower edge spoiler to lower the stagnation point to the base of the window, a similar (vertical height) point to where it is on the hatch.

Exactly my thoughts about the lift, hence the aero testing comment.