Washing a white car
 

Every time I wash my white boxster and it rains afterwards I have black drippings (probably not the best description) where it looks like the black area around the side mirrors is bleeding down the side of the car. Is there anyway to make this stop? Do I need to treat this area differently when I wash the car?

I just hate that these two areas look like crap so soon after I clean it up. This of course washes off easily but as usual it seems to rain within 24 hours of me washing it each time.

I can't see anything fixing that short of a garage, I doubt a car cover will be effective but it's an option. Personally, if I was using a cover I would be diligent about removing said cover daily. They claim those bad boys breathe but I contend they will still trap enough moisture to create bigger problems than an occasional streak. Another easy solution? Get some mothers spray shine, if the vehicle isn't heavily soiled, you can spray and wipe in seconds before you head out on the highway.

I would guess that you have dust and dirt in the mirror hinge or behind the mirror itself that isn't getting cleaned when you wash the car. Try to really clean out the area around the mirror, including folding it and washing thoroughly. Unless you've been using shoe polish to keep the black plastic dark or some kind of black grease to lubricate the mirror, there shouldn't be anything "bleeding" off.

Blow dry your car with the leaf-blower.

have you had this car a while? Maybe the previous owner treated the black stuff with a 'black again' type product and a little rolls off when you wash.
I'd clean that with a Klasse All in One type product. Maybe even take the clay bar too it while your washing.

Sounds like you didn't clean the mirrors fully.