Not personally a big fan of tints on my cars, but I fully understand the necessity when trying to avoid heating up the cabin and overworking your AC. When I lived in Vegas, I had to tint my car (2007-2011) and at that time, the bees knees on tints was this brand called Huper Optik, not sure if they're still around. It was pricier than other options, but it was rated very high in rejecting/reflecting back heat.
What's your range on your M3? Is it an LR?
EDIT: I just Googled and it turns out, they're still around.
Huper Optik vs. 3M: Contrasting Differences, Showcasing Strengths Comparing Huper Optik vs. 3M window tint films, contrasting their differences, is awindowtintz.com
Yes I keep hearing about the 3m crystalline, ill look into the huper optik. It's looking like maybe I need to do 70% on Windshield and 30-35% on side windows and possibly the small portion of the read window, I actually am getting my front windshield replace this Saturday as I have a big crack going from one corner to the center, so glad I didn't do the tint already.
Yes I have the Long Range dual motor AWD tesla model 3 with Aero wheels with FSD