I'm thinking of taking mine off as it creates eddies at the back of the car causing it to get dirty more quickly. I personally don't notice any difference at under 100mph and I seldom drive much faster.
What do you guys think....

 

Since taking off my s wing, and putting the plain Cooper Sport wing on, I have noticed less dirt buildup below window glass....I also noticed less debris and dirt grime buildup under the grab handle as well.

I would say the upswept OEM wings raise the rear air flow and hence deposit more kicked up road debris to all areas above the license plate.......

 

I'm thinking no wing..easier to clean....

 

I had a 1966 Dodge van. No spoiler or wing. The back got dirty. That is the way of cars with a square back end. I couldn't say whether the stock S spoiler contributes are diminishes the effect, but I don't think you will suddenly have a clean car by not having any spoiler or wing.

If you really want to reduce the filth on the rear, get rid of the OEM brake pads. When I switched to Carbotech 1521 Bobcats, the rear stopped getting so dirty. It used to get dirty within a week, now it takes months.

 

Robin is on the right track. Joel the designer of the JS art Wing Tip for the MINI helped me understand the issues this way.

Most of the dirt that gets on the boot BELOW the glass is coming from the bottom of the car and the OEM Wing will not help or hurt the dirt issues below the glass.

However if you have every looked at the "C" pillar of the 1st gen coupes the rear side glass warps all the way around the back to the boot and on the 2nd Gen coupes it doesn't and there's that vertical "speed bump" on the "C" pillar. MINI/BMW did that to help reduce the dirt on the GLASS of the boot. It works well.

The JS art Wing Tip helps even more on all the coupes by stopping the air off the roof and OEM spoilers from leaving the roof of the MINI straight and causing it to push down the glass of the boot meeting and disturbing the air coming up from the bottom and limiting the collection of dust and dirt on the boot.

So to the OP, removing the OEM Spoiler will NOT make the boot cleaner.

 

My 2004 Cooper (white) did't get a fraction of the diet on the back the new s does. The spoiler is ment to hold the back down at speed. It causes a down pressure that causes edes at the back of the car. I agree the flat back does this a little by itself but the spoiler I bet causes most of it. i et you hardly get any dirt on the back of teh original VW.

 

I have the JCW spoiler on my 2007 and the "normal" S spoiler on the 2005. It seems like the back of the '05 is usually dirtier.

 

We have also found that this issue is based in large part on the type of driving a given MINI see's.

Around town avg speeds under 45mpg see more build up.

Those that see more highway time and speeds not so much.

 

I switched to a Cooper spoiler and the amount of crap built up on the boot is about the same I would say (although sometimes it seems like there is less to clean, maybe its just my imagination).

The brake dust thing is an interesting point. If/when I switch to low dust pads I guess that will be the big difference.

 

I've had no spoiler and now the R53 spoiler. I also run Carbotechs all around. I've noticed no difference in dirt build up. Car is clean in the driveway and the rear glass/boot are dirty after just a few miles of around town driving. Drives me NUTS! Thank goodness for the CA Duster.

 

I have used rejex on the rear glass and have noticed less dust build up. I do mostly highway driving but again with the rejex even after it rains the car seems cleaner.

 

I replaced the original S spoiler on my '04 MCS with a JCW Rear Wing and the dirt reduced dramatically. My '09 JCW now has the JCW rear wing and there is virtually no dirt on the rear hatch.