[GTA SA] How to make a vehicle's windshield/windows reflective for ENB?

[kisgame]

I have a little problem. Most of the downloadable vehicles for SA works great with ENB, but there are some cases where reflections are partly or entirely missing. I want to edit these models with non-reflective parts to be reflective - especially the windows on cars. I've tried modifying reflection, lightning and texture values on these models, but none of them made a change for me. What does it depend on whether a given geometry does have reflection with ENB or not? Keep in mind that I'm a rookie modder. Thanks in advance!

[ENBSeries]

The best is to check how models with reflections are made, which mesh format. I dont remember now for sure, but definetly they must have vertex normal and no shaders attached. I'm not good at native modding of the games, just see them from renderer side, so can't help much.