GreenWorks 1900 psi pressure washer and multiple foam cannons.
I use 3D Pink Soap, which is a pH neutral soap. Still playing around with mixture, but goal isn't simply to get the "foamiest" foam, but to lay down a solid coat so the soap has time to loosen and encapsulate any debris on the car.
I rinse, then foam, then rinse again. Then go to a two-bucket (2 gallons each) using Wolfgang's Uber Rinseless wash to wipe car down. Typically only need one (1) 16" x 16" Gyeon Silk drying towel to dry my entire car (except wheels, I do them separately).