Ron,
I guess I wasn't thinking particularly well. Too much urgh, everything really. My justification now would revolve around the relative angle to the downward swooping hatch-line. I'm likely wrong, but it seems that the step doesn't make that much of a difference to the profile, esp as the point of these spoilers is to create high pressure zones by basically stagnating the air as it flows down the hatch. Now that it'd be worse with a smoother edge, just that it doesn't seem worth any increase in price for that mod to be done. I really like this spoiler as I think it will work well with the next level up in aero, like the dual-element wing on the orange race car with wide zgs and rota rbs (the link to which alludes me). Edit: http://forums.hybridz.org/showthread.php?t=148438&highlight=track+car
Either way, I want one.
Dave