Glass problem - incorrect refracting

As U see at image I have incorrect refraction on the Car glass material.
Some like loupe effect. How to solve this problem? Glass is the separate mesh.

How thick is the model of your glass? That might make problems.

And make sure it has a depth.

an IOR of 1.5 is way too much for car window glass. Bring that down to around 1.1 or 1.08 and we might have a solution.

A IOR of 1.5 is not to much. Most glass materials have a IOR around 1.5, but windows are so thin so the refraction is barley noticeable (many times it’s not worth using a refractive material for windows because it doesn’t make a difference only longer render times). The problem is probably related to the thickness as Julianh mentioned.