I have just given the liz a once over and noticed a tiny speck of yellow gunk on the cap. Is the fabled HGF mayo a thick white or is the above an early sign?
I have trawled the previous threads but can't find an exact description of this residue.
Don't panic just yet. It could easily just be condensation. Keep an eye on it though. Clear the mayo off and take the car out for a good 30 min+ drive. If mayo is present afterwards, its time for further investigation.