Wash the car a couple times a month, more if necessary. Soap and water work pretty well and will be safe. Even if it's already built up, soap, water, and a sponge will be fine. I find it's easier to remove if it's wet, so soak it a while if it's dried.

Agreed. Had to do this recently and was amazed at what soap, water and a sponge did. Used a toothbrush for hard to reach and small spaces.

Btw Pacific rhododendronis our state flower. Not the green crud on the car.

Regular washing. A pressure washer, used carefully, will get the crud out of the nooks and crannies.

I guess I assumed it would need something more than soap and water. Sometimes simple is best, I guess. Thanks.

Could’ve fooled me. The green crud seems far more prevalent.

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I know. At least it's a pretty color.

Take it to a detail shop for an exterior wash and wax.

Mr. Detail in Ballard did a great job detailing my wife’s Subaru. They got all the green crud off the exterior and all the pet fur out of the interior. Great tint job too. Highly recommend.

It’s pollen and dust and then moss can grow from that. Maguire’s car soap works fine on it. My ex once bought an old ford focus that had been sitting under a tree for years to restore. It was covered in moss and we genuinely thought the car was green in color. Washed it and it was red. Welcome to the PNW

It’s the bane of my existence. I have two cars and a truck that do a little bit of sitting throughout the year and 5 vehicles at work that are only parked outside and it builds up a ton.

I guess sarcasm is over the head of some folks here. Yeesh.

Pressure washer