Hi Grant. Sporting's have colour coded bumpers right? Surprised that these have faded any more than the rest of the paintwork tbh. Sounds like the whole lot could do with a polish if it's gotten to the fading stage.
Best bet is to polish by hand, or if you know someone with a machine who knows how to use it, machine polish the car using a fine finishing polish. This should be enough to restore the colour and return some gloss. To prevent the fading happening in future, lay down some good protection on it (wax or sealant), and try your best to keep on top of it in the future - wax/sealant every 4-6 months for example.
HTH.
Matt.