Ok I can see both sides of this, the reason mkv gtis have a flexi in the downpipe is because of the way the engine spins/rotates when running and under load it moves back and forth on and off throttle thus requiring a flexi in the downpipe to stop excessive exhaust movement
The Scooby engine spins/rotates and moves in a complete different manner whilst driving and under load due to its flat 4 configuration hence why aftermarket exhaust manufactures don't need to include a flexi joint into the system