I had a carbon fibre one a few years back, had it on 2 weeks and then nudged a kerb at Argos on Hailsham!
One smashed splitter and £250 down the drain!
I know what you mean about the plastic ones though mate, they are saggier than Martyn's back door!
I am thinking of getting another Carbon one. I might see what Saj can come up with at Jap Performance Carbon.