I just took mine off this weekend, but I didn't take any pictures of it and I'm out of town now. Basically though, all you have to do is look at the routing. If there is a crossover running from one side of the car to the other just behind where the tips are, it is most likely stock. There is one other manufacturer that includes the crossover, but the Corsa doesn't. If it's still on the car, you can look into the where the tip is. If it's stock, you will notice that the tip exiting on the driver's side is actually coming from the muffler on the passenger's side and vice-versa.