Many body panels are clipped on, I'm not sure how much those types (front fender/quarter panels) really help in a crash.
In addition, the plastic body panels on a Fiero or Saturn may do little in a crash.
I would think that the two examples above would be excellent candidates for body skin replacement using fabric covering (aircraft/hovercraft style) with a light-weight frame for attachment points underneath as needed.
http://www.calgaryfieros.com/FIERObuild.htm
Everything except door protection is here, it's like a Jeep "as is".
http://www.skyroadster.com/forums/f5...tection-11693/