Ok here's an update. Brought the car back to the garage after three weeks drivingto check the filter again. A little bit of black spongy stuff got in bottom, but nothing like before. It was totally clogged up the first time. A note of caution,when this filter is removed air gets into the fuel system and it takes minutes to restart. If the battery is weak or not fully charged, it will just die. So if anyone is doing this as a diy, have some jump leads handy. Thanks everyone for your help and I hope the above information is useful to someone. Happy New Year.