Although one of the posters above was correct that "any modification to the exhaust system is illegal (aftermarket)" everyone knows that we can all disregard that. Virginia currently has a law in progress to allow modified engines, seeing as almost everyone I know has mods to theirs that aren't factory. (It's well past due anyways)
Anyways, I've talked to Borla since I ordered mine and to their knowledge there is no "side exhaust" law that prohibits where the exhaust is. I looked for any Virginia laws and there are none IMO. As long as it PASSES EMISSIONS you should be fine. Either that, or find a good friend who does your inspection/emissions and you'll be alright as well. Anyways, why should it be illegal? Think about the Roush Mustangs - they are a production car and they're not illegal? Hope this helps!