Some facts: The Petro car washes without the tracks will be about 6.5mins/car. The ones with the track is less than half the time/car.
There's two in my area, and I'll always drive by the one without the tracks--if the lineup is huge, I go to the one with tracks and by the luck of the draw, the tracked-wash is generally empty when I get there.
Both do a decent job, and I don't "think" the tracked-system does an undercarriage-wash. Don't quote me on that but I never feel the undercarriage being washed. (Dufferin/Langstaff Petro)
When called an idiot sometimes is better to be quiet than to open mouth and remove all doubt.
Man who walk through airport turnstile sideways going to Bangkok.