I have a pretty bad fuel leak on my Golf GTi mk2. The fuel lines come from the tank and then disappear up into the car under the driver's seat sort of area, coming out under the air intake under the bonnet. The leak is coming from somewhere where the pipes disappear up into the car. So I need to replace the two pipes. The pipes are plastic. Where on earth can I find replacements for these pipes?! What size are these pipes, inside and outside diameter? The only ones I can find are rubber and seem much too big! Please help if anyone has had this problem or can offer some advice! Petrol is pricey enough already without it leaking away!