I agree, all good stuff! The only procedure he recommends I would not follow all
the time, is cleaning the vehicle from top to bottom. This is definitely the way to go with most paint colors, but white paint reacts differently many times.
Mostly, this only applies to white vehicles that are dirty, or have road film on the lower section - below the belt line.
Starting at the top creates lots of soapy "runners" that, as they slowly creep down the sides, seem to strip away the film way better than your scrubbing can accomplish. Then, when you get down to washing that part, you can still see the really clean runs it made after you have scrubbed it and rinsed.
Depending on the paint and detergent you're using, these extra clean "runner" areas may be faint or extra bright and noticeable after washing and rinsing - like a bad paint job.
On my white E350, I've taken to washing it from the bottom up - beginning with the wheels and wheel wells. Then, when those soapy "runners" float down the sides as I work my way up, any runs are less visible, if at all. I don't know why this seems to work, but it does.
If no one here has ever experienced this, I will assume I had an automotive nightmare and made it all up
Oh! I almost forgot the best part..
I had a '92 Delta 88 demo I had to wash after our first snowfall that winter. It was white. All I had on hand was powdered Tide clothes detergent - soooo....
Wellp That stuff stripped all the gloss off all the black body moldings. It stripped all the wax.. all the sealant.. and darn near got the clearcoat. I'm convinced if I had not rinsed it as I was going - in sections - the clearcoat would have rinsed off too.
Live and learn..