ICEBERGS

Last week I was coming back from Agusta GA, and was coming down I-20 , I was pacing this guy in Mazda 6 at around 100mph, when all of a sudden I hear this very loud thump, so my first thought was that I blew out a tire or hit something in the road, but the car remained controllable and i didnt smell rubber or notice a difference in driving so I pulled over because I was concerned that I might have hit somthing and damaged my bodykit, so when I pull over I inspect for damage and see nothing, so I kept looking and found that the lower part of the driver side fender liner was torn completely off...does anyone know where i can get the left front inside fender liner at a reasonable price? I have tried the dealer here and they quoted me at 83 dollars, I wanted to consider my options before I bite the bullet and shell out that much money for something that probably costs cents to make!!!!