I have an '03 coupe with 91,000 miles on it, and am thinking about a possible replacement. I love it, but one of the less endearing qualities is the way road scum or dust quickly accumulates on the rear end, the so-called 'dirty bum'. Just wondering if the Clubman is a little less susceptible to this, with the slightly longer body overhang at the rear, and the more square angle to the road....
Anyone able to give me an empirical observation on this, any experience? It might tip me towards a Clubman if the rear stayed cleaner, even though I have noticed that visibility to the rear is less than with the coupe, and the rear opening is smaller than with the coupe.

 

Just as bad. Horrible. Worst part of the MINI IMHO.

 

+1!!

 

Do you think ordering the rear spoiler would help any? Or rear mud flaps?

 

i was just browsing a few threads here about our dirty butts caused by air pressures and turbulence that throws dirt on the flat rear similar to suv's and minivans. seems the mud flaps or oem spoilers may not make much of a difference. autoxcooper is claiming improvement with their wingtip extensions, though. i'm especially interested now that i deleted my rear wiper for a back-up cam.

 

It's just a fact of life with a station wagon. Some are better than others, but all suffer from a dirty rear end to one extent or another. With all the junk on the roads this winter, it only takes about 10 minutes of driving before the rear end is covered with a layer of dust, salt, and mist. At least the wipers look cool when they wash away that gunk!

 

Yep. The Clubman's butt gets really dirty. As bad if not worse than the hatchbacks.

 

What do y'all think about this wingtip extension thread? Sound credible?

https://www.northamericanmotoring.co...n-a-month.html

 

I traded in my 05 JustaCooper on my 08 Clubbie. I can say from personal experience the justacooper rear got a little tiny bit dusty compared to my Clubbie - which is downright filthy within about 5 miles after any wash.
Only thing wrong with the car, IMHO.

 

I concur about the Clubman's propensity towards a dirty bum. I've only had the car 3 days and washed it the 2nd day. Drove to work the next morning, car looked great, EXCEPT the rear end, it was filthy. I think I'm going to start carrying one of my wife's plant misting bottles and a spare towel...

-RW-

 

Has more to do with the vortex created by the lack of a rear trunk. What we are experiencing happens with all hatch back designs including VW GTi's, Mazda and alike.

If you want to eliminate this, maybe will have to look at the BMW 1 series coupe or sedan ?

I removed my rear wiper/motor all together and plugged the hole, effectively taking another 4 lbs off the rear of the car. Besides, it seemed like more often than not the wiper just ground the dirt in across the glass like sandpaper making a permanent scratches.

When I was kid, out stationwagens had an aluminum deflector that actually took the air off the roof and directed it downward against the rear glass forcing cleaner air to push the rather dirty air flow downward and away from the boot....

I suppose if you wanted to remove the rear wing, a similar device could be fabricated and installed.

 

If the rear end of the Clubman is more vertical to the road and more squared-off where it meets the roof compared to the coupe, that's why you're getting more dirt on the Clubman boot.

The reason for the dirty boots on our car is because of the way the airflow behaves when it passes over the rear edge of the roof. When the "boundary layer" (the layer of air closest to the surface of the roof) reaches the end of the roof, it has too much momentum to make the sharp 90° downward curve to hug the back of the car. Instead, the boundary layer separates from the surface of the car and goes flying off behind the car, leaving a large area of stagnant (non-moving), low-pressure air around the boot. Dirt from the road is kicked up by the airflow passing underneath the car, and since the air around the boot is stagnant, the dirt just settles on the boot rather than being blown away before landing on the boot.

The purpose of the "wingtip extension" mod is actually to *cause* turbulence as the boundary layer passes over the wingtip extension. This causes the boundary layer to "tumble" through the air (become turbulent). A turbulent boundary layer is much less likely to separate from the surface of the car than a smooth boundary layer, so you don't get that large pocket of still, low-pressure air surrounding the boot.

In reality, even the turbulence from the wingtip extension probably isn't enough to *completely* prevent boundary layer separation, but it's going to reduce the size of the stagnant region significantly. As a result, the dirt kicked up from the road has a better chance of encountering the turbulent boundary layer (which is closer to the rear of the car than the non-turbulent boundary layer was) and being blown away before it has a chance to settle on the boot.

 

A Back up CAM in place of the wiper !

How cool is that!

Two Thumbs Up !

 

i concur. here's your proof...



but to it's defense, you get used to the center bar and can fit just about anything (that i've tried) into it.

you're get a dirty rear no matter what...

 

thanks, and insanity has replaced reason in this mod. here's pic before the recent snow, salt, grime.

 

That sure is a clean look with no wiper, but I DEFINITELY need them on my WHITE 09 Clubby here in Michigan -- especially THIS year!

Interested in the deflector concept though -- I remember them on station wagons too, but there's that wind resistance thing...

Chers,
John D.

 

Actually, adding a spoiler at the rear edge of the roof could *reduce* the air drag on the car. The large stagnant low-pressure area that forms behind the car in its stock configuration causes a lot of drag, because the high pressure at the front of the car coupled with the low pressure at the rear of the car causes a force that pushes backwards on the car. It's like blowing on a balloon - the pressure is higher on the side you're blowing on compared to the side you're not blowing on, so the balloon is forced backwards away from you, toward the low-pressure side.

If you reduce the size of the low-pressure area behind the car by adding a spoiler, you'll reduce the pressure differential between the front and the rear of the car, and this will reduce the backwards drag force on the car.

 

The back of my R53 S doesn't get as dusty as the one in the Clubman. I think the roof spoiler helps some.

 

Anybody else wondering what Scott's IQ might be ??

 

more than mine.

 

Mine, too ... and mine isn't too shabby.

 

Nah, I just got lucky that this thread came up while I'm taking a Fluid Dynamics class as part of my master's degree curriculum. Two months ago, I wouldn't have known half this stuff. (and six months from now, who knows?)

 

they say we only remember 10% of what we learn in college. it's less than 0.5% +/- 2% for me. i forgot all that liberal arts stuff. ask me about my mini's mods, 99.9% retention.

 

Ding! Ding! Ding!

You and me both.

 

If you read any auto racing or race car design books of the 60's you'll get the whole theory of boundary layers, frontal area, coefficients of drag etc... never had it in school - read it cause I was interested, and that's why it stuck... Alfred(?) Kamm 'Kamm Tail' (http://en.wikipedia.org/wiki/Kammback) was popular for a while there, Ferrari 250 GT SWB 'Breadvan' (http://www.supercars.net/cars/3181.html) perhaps the ultimate and the Vega wagon of the '70s... Of course without the schooling, I always thought that the spoilers had to do with downforce at speed when cars tend to want to become airplanes, and they were a trade off -- more wing, more drag, greater downforce, less wing, less drag, but also less downforce... BTW, I bet the rear ends of all those race cars get plenty dirty...

Cheers