Ok finally got the car out into the world...
Corners are just rough cut still as the cutting blades has to much jitter when cutting corners that tight. So that will have to wait for a smaller cutting wheel.
Good news is there is no movement in the bumper at 99.99kph even passing near trucks and walls. Though I think double sided tape or sealer maybe required at some stage just to keep it in place if it get physically knocked. The tray can pop out of place slightly but not actually seperate from the car.
If you look closely you can see the three pairs of holes in the seam above the cut where the cable ties (also known as greatest invention ever, after the car and gas and...) have been used to make 3 mounting points for the new under tray.
After the new exhaust is in I'll most likely take out a little more and make a new rear tray from the diff back. There will be no need for the heat shield across the car since the exhaust will be tucked up one side like the sedan. That should also make the diff visible from the back too so will have to shine it up, ok maybe not.
exhaust tips are blue but just dirty. Just be thankful the bumper is cleaned, and that was only done to remove all the dirty hand prints from doing the work.