Car has developed a sudeen midfire.... Came on without warning and is a mystery, new plugs, oil filter and oil 2 weeks ago has been fine... is fine when started runs smooth but once its at operating temp it starts to misfire and idle rough, then when its gets going smooths out.... then at idle rough again and lower rev range. I am suspecting maybe spark plug leads or a fuel filter blockage.... any ideas?

try closing the gap between all of your spark plugs, coz if you buy new ones they are not usually set properly for VL's (had the same prob mate).