Thank you for the comments!
That's a 3" DP to a Jetex midbox. It's loud which you might not be able to tell too well but I love it, it's the perfect tone and rasp for me!
It's easy in concept to modify the downpipe, you just have to know someone who can weld. It's unfortunately sounding like you won't get away with not cutting it, which is a shame for an off the shelf item!