I considered the "cool" red polyurethane ones, but it's REAL expensive, at least for road rally activity.  I went to Canadian Tire and picked up a package of 2 TRUCK mudflaps for $45.  They are long and wide, and have no stupid pictures (Yosemite Sam, Taz Devil) or brand names on them, they are simply black, and thick.  I bisected each one down the length, and now I have 4 mudflaps that I can get down to an inch off the ground.  A little more width would be good, so depending on your budget and car, buy up to 4 flaps, and cut/trim as you need.  The rubber is good an flexible (not plastic), and 1/8" think or so.  Should last quite a while.

Maybe Keith could run the Tazmanian Devil flaps. (OK, wrong country, I know)  : )

Cheers,
Craig