Dirty Rear Bumper

frankzlin79 · 06-30-2009, 08:32 PM

Every time I wash my car, I notice that one of the most dirty places on the car is on the upper portion of the rear bumper (along the entire length of the upper rear bumper) where the trunk mates with the rear bumper. Why is this area sooo dirty? Is it the airborne exhaust emissions that get blown by the wind and then hit the upper rear bumper?

MTROIS · 07-02-2009, 08:59 PM

With the diffuser, etc... located there, the back of the car is expectedly the area where most of the air disturbances are located and thus where the dirt will be accumulated. A rear view of the car when in a wind tunnel would be the most illustrative way of seeing this.

06-30-2009, 08:32 PM	#1
frankzlin79 Lieutenant Colonel 265 Rep 1,696 Posts Drives: 2018 M3 Join Date: Oct 2008 Location: Houston, Texas iTrader: (5)	Dirty Rear Bumper Every time I wash my car, I notice that one of the most dirty places on the car is on the upper portion of the rear bumper (along the entire length of the upper rear bumper) where the trunk mates with the rear bumper. Why is this area sooo dirty? Is it the airborne exhaust emissions that get blown by the wind and then hit the upper rear bumper? Last edited by frankzlin79; 06-30-2009 at 10:10 PM..
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07-02-2009, 08:59 PM	#2
MTROIS Major 188 Rep 1,153 Posts Drives: on the wrong side of the Ocean Join Date: Jul 2008 Location: New Jersey, USA iTrader: (0)	With the diffuser, etc... located there, the back of the car is expectedly the area where most of the air disturbances are located and thus where the dirt will be accumulated. A rear view of the car when in a wind tunnel would be the most illustrative way of seeing this. __________________ 2019 M2C MT (ED + PCD) \| 2008 M3 Coupé MT \| 1995 M3 LTW MT \| BMW CCA HPDE Instructor
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