[brucepick]

I've numbered the panels for reference in this thread.
All panels are overlapped (front one below the rear) like shingles or fish scales. The overlap joining #2 and #3 is large, due to the locations of the existing available attachment points. They're not in an even line going across the underbody.

Panel 1: The oem front panel section. Aluminum + rubbery plastic.
- Or in my case, the aftermarket aluminum replacement panel, by Scott. AKA klr3cyl on Insight Central. It replaces the aluminum plus rubbery plastic oem front section.
Panel 2: Goes from the rear of #1, to about a foot rear of the firewall.
Panel 3: Goes from the rear of Panel 2 (a foot rear of the firewall), to a point about a foot forward of the rear wheel wells. About 48" lengthwise.
Panel 4: Goes from the rear of Panel 3 (about a foot forward of rear wheel well), to the crosswise narrow air deflector that's mounted at the rear of the gas tank. Air deflector = attachment point.
Panel 5: Goes from the air deflector at rear of gas tank, to the rear bumper lip.