hi gents currently drive mk3 8v 98reg with a stock sound system wich is ok but once turned up has a lot of distortion and sounds terrible.so i am after upgrading my speakers front and rear and i would like to put a sub and a amp in boot .could any of you guys give me advice on the stuff i would need i have a pioneer keh p4900r hu and a matching 6disc in the car are they any good or would i need a new hu and cd player also i am on a budget . any advice appreciated cheers gents .andy