Dirty Hatchback Arse During Winter Months?

[TheZProjekt]

I don't know if anyone else noticed this on their 2nd gen hatch but the back of my indigo dark blue hatch gets insanely dirty even within hours after a car wash, especially lately during the colder months. I think the washer fluid at the back just leaks down onto the rest of the car and freezes or mixes with dirt and salt or something.

After less than a week, the rear license plate is illegible at night and covered with dried water with salt, dirt and whatever. The entire back of the car is literally white/grey and the front stays so clean. Makes very little sense to me, unless this is some sort of aerodynamic flaw or something. Not really fishing for help but just curious as to the possible origin/s of the problem.

[greaves82]

Its just the aerodynamics of the vehicle and the way the wind moves after its passed over and around the car

[Seshan]

Poor aerodynamics, it's same for all cars, but cars with flat backs are worse. Look at transport truck when you are behind it and the roads are wet you will see all the water fly up all over the place, it's not because of the wheels. They only way to stop it would be make the end of the cars into a point so they air flows over them smoother,