Mud flaps

[Teutonic_Tamer]

Or about £25 a pair if you are handy with spanners!   

Want the part numbers?

[mrlapou]

Thanks, I'll call the dealer for an exact price.
My BMW 3 series required holes to be drilled, what a pain !! 
Those on the A3 were dead easy.    A few clips that pressed together, then a screw into the plastic body work trim.

[Teutonic_Tamer]

The Mk5 Golf uses existing fittings, ie, remove a couple of torx screws, offer up the mud flap, and then reuse same fittings.  They also need a couple of holes punching, just with a bradawl though, the fronts are through the plastic wheel arch liner, and the rears are through the carpet-type liner.  If you can change a wheel, then you can fit the flaps.  They even come with very good, detailed fitting instructions, with pictures.

HTH