I thought I might share this bumper build here in case anybody is interested in doing their own bumper. On this particular bumper build, I applied my own style, but incorporated what I thought would improve my aerodynamic efficiency based on what I know about aerodynamics. I did not base this off of any wind tunnel or pieces of string taped to the car, just what I know about aerodynamics. I probably just got lucky on the design, because it certainly improves my fuel efficiency at higher speeds.
Here is a pic of my finished bumper:
All I did was mask off my original bumper with masking tape, and spray it with some mold release. I cut out a piece of metal shaped like my license plate and taped it in, and I taped in a piece of 0 gauge car audio wire to fill the gap between the hood and the bumper.
Next, I wrapped it up in fiberglass, let it dry, and popped it off of my taped up original bumper:
Then I used polyester body filler to smooth things out. Polyester body filler works great with polyester fiberglass resin.
Here you can see how the bumper curves up to fill the gap between the hood and the bumper if you look at the right lower corner of the head light. The factory bumper just goes straight across, level with the bottom of the head lights. I also made sure to make a very tight gap between the hood and bumper, since I do not want any air coming into the engine compartment.
I primered the project with good two part primer, and test fitted a bubble type license plate cover:
Took a mold of it in two halves...
Painted my project along with the rest of the car
And here it is ready for the road...