Only way to find out is to try it....."Works on the black plastic trim on cars too; makes the part look better than new"....
Wonder is it will make the black plastic on the rear of the wheel fairings and the back of the Elio look like a shinier black. They look like they leave something to be desired on the E1C pictures that I have seen.
If anything, you can use the "B2B" and then wax it. Or since it's plastic, repaint it gloss black (or matching body color).