From searching the SCCA forums, some of the hardliners think that the rules as they're written make it illegal for the typical Subaru upper strut bar because it technically mounts in 3 places on each side.
An upper strut bar mounting via a plate in 3 different places will provide some rigidity in other axes besides just tension between the strut towers unless there is some sort of helical joint used. I guess they came out with a change a year or so ago mid season requiring just such a joint because of that. However everyone bitched because it basically makes almost every bar on the market illegal and they rescinded the change. Yea that rigidity is probably minimal in comparison to the cusco type ii bar I'm asking about, but where do you draw the line.
All I'm saying is there needs to be some clarification. If the upper strut bars everyone uses are legal, then there is an argument for the cusco type ii style lower bars.