Front airdam. I made lightweight alloy brackets from a bit of left over paver edging, held with factory screws in the bumper. The rest is plastic lawn edging that's been hard to get here, all the ones we had previously weren't suitable, this seems to be a new product and available in 3-6" heights. Mine is the 3".
It's a bit hard to see but it I like the way it reminds me of a NASCAR now
The rear bumper is the usual mess, so I did an axle back under tray. I folded the front edge and jammed in in behind a shroud or something back there, then zip tied the main section to the spare wheel carrier. The side folds up behind the exhaust heat shield, and then the back of the tray simply pushes between the bumper cover and the towbar.
The test run matched my best ever of 4.7l/100km, and I've since done 4.4l/100km as my best trip. So they seem to be helping.