The simplest impression comes from sitting in the car on a sunny day and comparing it to how it felt before, particularly after it has been parked in direct sun. For anything more precise, professionals use IR meters and published test data rather than hand-feel comparisons, which can be misleading because glass and film behave differently across the solar spectrum. If you want numbers, ask your installer for the specification sheet on the exact film that was fitted. To start, send a
Ask a local tinter whether they carry Kepler film or can get it. For more information, see quick quote.