When you build a custom car, the first thing you should always do is understand your goals -- if you want to keep the weight down, you probably shouldn't do what was done to this car...just read the seller's words:
The hand-built body is constructed of very thick fiberglass. This is no flimsy kit car; it is very solid and well made. There are no stress cracks visible anywhere. The builders even added a steel subframe to accommodate the additional width and length of the new body.
It may be all Blade Runner meets Tron on the outside, but inside you are treated to a stock looking Fiero interior, complete with automatic transmission shifter connected to an autobox and a 2.8 liter V6.
See another one-off fiberglass custom offered for cheap? firstname.lastname@example.org