I am looking to buy a mazda mx5 for the summer. I want a british model and in a 1.8. I saw this fine looking one for 2995 from a dealer. The car was spotless and had a new hood. He started it up first time and the engine sounder quite nice with no tapping or knocking. The problem is that i have owen two rover 216 and both head gaskets have gone on them, so when ever i got to buy a car now i have got a Habit of checking the oil for moyo substance. I checked the oil on this mazda And the dip stick wa showing clean oil but then i removed the oil cap and inside was this mayo kind of substance stuck to the inside!! Does this mean that the head gasket has gone? or on its way? or is it common to have a little inside the cap due to condensation? I dont want to buy this car and find out down the line that the head has gone. also there is no service history with this car!! Is hgf common in these cars? Thank you