Here's my quick writeup of my DIY mudflaps. Total cost including everything $18 (18 wheeler 1/4" thick mudflap + hardware)
THE MATERIALS: a bigass mudflap for an 18 wheeler (from NAPA, just ask for the biggest one they got... $12). THIS THING IS HUGE! That's a 36" yardstick layed out on it.
three strips of thin sheet metal ($0.10 a piece at my hardware store)
8 1" sheet metal screws
2 2.5" sheet metal screws
2 1" nylon spacers
10 fender washers
Tools:
a box cutter with a fresh blade
a yardstick/meterstick
drill
screwdriver
Mounting Instructions: THANK YOU RALLY ARMOR!
LINK
CUT EXACTLY IN HALF
CUT EXACTLY INTO QUARTERS
this **** is THICK!
What we're going for
Lay the fronts on the rears so you can copy the curve
Curve copied
Curve copied on both rears. Later you will copy the curves on both sides... you'll see what I mean.
Cut your sheet metal about this big
Fold it over and drill a smaller hole... I went two sizes smaller than my sheet metal screws. Your sheet metal screws will tap it and you want a real tight fit so your fasteners last long.
I have no pictures of fitment because there is no way I can help you over the internet after this point. You'll do it if you can do it, you won't if you can't. For me it's really easy, might be different for you. But here is more or less what my fronts looked like before I mounted them.
I mounted them per RALLY ARMOR's directions. I figured if anyone knew anything about mounting mud flaps for street use, they would.
http://www.rallyarmor.com/store/gc8_instructions/rallyarmor_GC8_classic_mud_flap_mounting_instructions.pdf
The rear installed. I wanted to keep the inside from flapping so I drilled a hole in the neighboring seam and threaded a ziptie through it. I also used the predrilled hole in the napa mud flap to mount the top.
SOME PICS INSTALLED