I'm enjoying this whole discussion! Lowe, you're supposed to credit the origin - it was Yvan who stated the 2 bucket method was one on each side of the car. I've mentioned before that Dr G doesn't use the 2 bucket method, but with 2 sons, I don't think David washes his own vehicles. The only reason I use that method is that I found a divided bucket at a janitorial supply store. This proves all paths can lead to clean cars - foam, single/two bucket, fancy wash patterns, ergonomics, etc.
Honestly I've never approached car washing with efficiency in mind, I put music on and have my Big Red Dog for support. Reviewing my process it's obvious I could cut some time and effort. I start at the top (like my daddy taught me), then do all the glass. That's wasted time and an extra trip. Then I pick a side (I like diversity more than routine), and do sections thoroughly. Every area I do, I do completely, meaning wash/seal/dry before moving on. I save wheels/tires for last because i HATE them...and sometime just wipe/seal the wheels, skipping rubber. That's why I'm experimenting with TPC. I take the drying towel infused with ONR and wipe down the interior, followed by Protectant Plus. With each wash bucket, I usually do 2 cars, a regular driver and the Garage Queen (small and easy), though sometimes I do the riding mower instead. I've also experimented using Wax or Instant Detailer instead of sealant - I don't see a huge difference in look and do my cars too often to really judge durability. I find car washing cathartic - it's good exercise, outside, and when I'm done I can see what I've accomplished. A compliment from my wife is just the cherry on top! I've found few things in my professional life that provide as much satisfaction or instant gratification.