Bro to make things simple, if you are looking for significant sound improvements on your current exhaust. Either operate your muffler(your remus catback) , still loud not enough operate your stock midpipe. As they cut open from the top there is no way LTA is going to prove that your exhaust has been touched unless they jack your car and remove your entire exhaust system which will never happen at all. Getting stopped for loud exhaust is a common thing, whether they can find fault with your exhaust is another. Plus you have a cert to prove which makes things much more difficult.