Its not technically "street legal" but as long as you don't go doing stupid things the chances of getting in trouble for it are slim. My cousin runs the Flash Pro on his 07 Si. He set up a launch control with it and was going to use it to help tune a turbo build, but that got reversed due to turbo placement not being ideal with the set up he initially got. He's hoping to have it turboed either later this year or early next year though.