Ford Ka - Paintwork/Glass damage?

[GreaseLightning]

These are pics of my Mum's Ka.

A possible cause was wet concrete dust when it was parked underground.

It's unclear in the pics but the visible trails actually sit proud of the window and paintwork.

Does anyone know how this can be got off?

 

[dotty]

What methods have you tried already mate?

 

[smeg]

You may find you will damage the window even more trying to remove whatver it is already on it

Have you tried a pressure washer? high pressure water sorts most things

 

[GreaseLightning]

I hadn't tried anything tbh I just took my Mum's word that it was hard to shift. I got a response from someone on the other forum suggesting Meguiars Clay and hey presto! Cheers for the quick responses anyway guys.