Thanks Sid and Jon. Happy to do the work myself though as long as it doesn't involve welding. Sid it looks like your rear exit AR system is entirely different, nice work to turn it into side exit system though

Mine are round silencers as per image above with a AR prefix part numbers.
The only part of the factory sports (AR?) exhaust on a Brooklands 3.7 Roadster I saw last week was the slightly oval diffuser tailpipes. They were a good half inch wider than standard. Didn't have chance to see differences underneath but heard the deep throaty sound

I have a couple of ideas to spread the leverage load on those "L" brackets when I make up the extension plates, maybe even fabricated all in one bracket and bobbin support plates bolted to the OE captive double stud plates that fit inside the chassis rails.