Congrats on your new M3!
I've been driving my M3 for two years now, live in OC, and never felt the need for glass tint. OEM windows are dark enough, and the Tesla climate control is probably the most efficient I've seen. I just use a good windshield shade for when I park outside. My advice would be to save your budget for clear bra PPF and Opticoat which benefits have paid off many times for me.