Wind screen cleaner

Thank Mate will try it right now

A simple and quick way to remove grease is to put some diluted baby shampoo in a spray bottle.

Possibly a type of adhesive/goo used to try to get a suction pad to stay on the windscreen in hot conditions? I used a clear pad from Mr Stickee at one stage & when I removed the dash cam I left a difficult to remove goo possibly like you describe. Pretty sure that eucalyptus oil made short work of it, so perhaps try that if other suggestions fail.

Yep , if you have any 'aftermarket' window tint you should use nothing but what the tint installers use , that being clean water with a 10% metho mix .....