Hello,
I've determined that the approximate frontal area of the Scion xA is ~18.01 square feet. [See adjusted number below] I inserted this photo into DataCAD 12, scaled it based on the measuring tape just below the bumper, and I then carefully traced the outline of the car with a polyline, and the hatched it with a 1'-0" square grid.
Now, there is some distortion due to the camera being at a point (this is not a true "elevation" view). To minimize this, I used the zoom lens on it's longest focal length, and tried to position the height of the lens to ~1/2 the height of the car. The height scales to ~4'-2 1/2" whereas the specification is 60.2" (~5'-0 1/4"), and the width scales to 5'-1 7/8" vs 66.7" in the spec. so the actual area is like a little greater. In fact, the width is ~19% low and the height is ~7.75% too low, so that averages to 13.375%, so:
18.01 + 13.375% = 20.42 sq ft
[Edit: I will take another photo with a longer lens to try to reduce the error, and post the results later.]