STI Front Lip Installation
If anyone else buys the 2017+ STI Front Lip (Under Spoiler part no. E2410CA010), you should note that the instructions provided are for the pre-facelift model. In the main, the procedure is the same, but template A has no bumper curve to follow and template F doesn't go where the diagram suggests. Use a marker pen to clearly mark the two 'pre-arranged marks' in the bumper that look like crosshairs and offer up the lip so that you can mark the correct positioning of holes A and F on both sides. Otherwise you will be drilling in the wrong place.
I also strongly advise using a pistol-grip electric screwdriver with hex shaft drill bits as the slower speed offers more control and it doesn't take much effort to go through the plastic. Even when on axle stands, there isn't really room to drill upwards using a full size electric drill. I couldn't use a 9mm drill bit for the final opening up of the holes so I did them by hand using a hand reamer.
After the holes have been done and plastic rivnuts inserted, use the two big clips in the 'pre-arranged mark' holes to hold the lip in place, then screw in the end flanges, making sure that the fit around the corner is good. Then you can screw in the bolts into each rivnut. There is a small amount of give if your holes aren't exactly in line.
The final result is very pleasing and looks better than some of the cheap clone offerings I've seen on eBay.