We have the same track at our pack race. For my Scout's cars that are competing, the rules state "All four wheels touching & flat across the tread". Here's the kicker, also in the rules "No rail riding". I asked about this, and pointed out how easy it would be to use stock non-straight axles, and have drift one direction or another, by pure luck. I asked what happens in the case that a car drift/rail rides just by luck? I was told by the "official starter" every year (assistant Scoutmaster) that "Well, we'll keep our eyes on the competitive cars, and if we see any of them riding a rail, we'll just use plyers and start turning axles until they don't anymore". Yikes! So naturally, we tuned the competing cars into straight runners (+/- 1/2" over 4'). I built a couple extra cars this year (pack rules compliant with the exception of straight tune). One of the cars, is identical in every way to my Tigers car, except it's set @ 4" over 4', and will ride on the outer rail. I built it specifically for a side by side race with the Tiger car, to see the difference in performance between the two. The downfall of what Kinser mentioned, is that we can't run any washers/spacers of any kind, so no reverse DFW for us, and we will be letter riding.