Did mine last night. Took the lazy option and ordered a box from UKlegacy. Didn't actually realise how badly the car was performing before changing the pipework. Boost was lazy, was very laggy when coming on and off boost (could actually hear the change when boost finally kicked in at times).
Now is a different story. Car is so much better to drive. Boost has significiantly improved, VOD has reduced, and lag has much decreased.
I'd recommend this little mod to anyone. Plus for a novice only took me 15 mins to swap the boxes in and out.
Alan.