Since Solo Nationals doesn't have any wheel-to-wheel action at all, that might be the differentiation.

I liked the All American Rejects livery, the purple fading to black was pretty cool.

I'm trying to remember since it's been a few months (usually have a family member acquire one for kids birthdays, both my sons like it), I think the decorated areas seem sweeter than the base frosting, but I end up remembering the mousse filling in between layers more.