G3 compound and a damp rag using lots of elbow grease is the best thing to clean a minging poptop followed by a good coat of wax Anything more agrressive than that will leave grooves to fill with muck which will then accelerate mould growth and help degrade the surface If its that far gone it wont clean then flat it back and paint it
I've been using a lot of elbow grease ... Had to do this over a series of nights as after a while RSI kicks in and I'm dead
