Thanks for the suggestion MartinK, I did think of this, but my husband ruled against it and said for the cost involved he'd prefer to replace the pipes!
Urban Panzer, I don't live near the sea, but the car came originally from the west coast of Scotland, so perhaps that's why the pipes have rotted this quickly. The last 2 winters have been horrific here too, with several weeks of snow and bad ice and the gritters are out constantly doing the roads. Perhaps that has also had an effect on the car, as it is impossible in -17 degrees to hose it off each week to keep the salt down!
I've got 2 pipes to replace the original, but unfortunately they won't fit, so back to the retailer and the drawing board!!