That dirty water is the rinse bucket from a 2 bucket was setup. If you aren't familiar with a 2 bucket wash, the intent is to always keep one bucket with clean soapy water. The other is used to rinse/scrub the crud out of the wash mitt. Each bucket has a grit guard in the bottom. This helps to prevent dragging dirt all over the car. Works pretty well.
Just after the wash, looks good. Still have a ton of work to get the chassis back cleaned up.
And dang! 1878 miles on this build! Time for some maintenance.
So up on jack stands C10CJ went.