Ohmess

Now I get it.  

Yes, my car has a multitude of electrical quirks and I have spent several years working through them. 

I am still considering window tint. What effect does this have on the ability to tint the window?  

I own a 1972 BMW with a curved rear window, and am looking for a high performance tint that can be installed in my car.  Another owner of this same model car posted this same question ten years ago; I am reviving Rob's old thread in the hopes that perhaps some new products have come on the market.

I have Huper Optic film in another car, and have been very happy with it.  I believe, however, that Huper Optic film cannot be stretched to fit my rear window.  I am specifically seeking a product with similar performance, that could be installed in my car.  Here are several examples of the car in question:

 https://www.e9coupe.com/forum/threads/southeast-sharkfest-2020-e9s-unite.33484/#post-276652

Here is the link to the previous discussion of this same question: