[aerohead]

They would be configured to blend right into the belly pan and skirts, also forming part of the sides of the wheel fairings, before and after the rear wheels.
Ford Motor Company testing of the Probe-IV and V indicated no value for wheel fairings behind the front wheels.
The Home Depot has a selection of aluminum roof flashing which would work as well as the advertised materials you've shown.
3M markets a commercial automotive adhesive, available only at automotive refinishing supply houses, where your local body shop gets their supplies.
This adhesive is what body shops use to bond 'ground effects' kits. A few pop-rivets hold the composite pieces in place until cured, then the rivets are drilled out, and the holes sealed and smoothed.
Viking's axle fairing is permanently bonded with this 3M product.