I would think that if you delayed the start of the wash you could achieve the dwell time that would help. High pressure would be desirable but not as important as giving time for the chemicals to work.
And please do share what in your opinion is the 'right' wheel cleaner chemical.With the right wheel cleaner 15 seconds should get you decent results on the majority of the vehicles.
As the car is driving in, I see the green tire/wheel chemical, then what appears to be a medium pressure water spray from a stationary manifold - also as the car is driving in - what is the function of that?Watch this video of this Soft-gloss with Tire Chemical at the beginning and the prewash you don't need to have the nozzles oscillate just have 3-4 turbo nozzles instead and the speed is adjustable for the high pressure pass http://www.youtube.com/user/hyvahyva#p/u/40/KVX6Zk7uEpg