You’re in the SGV. Check out the nice owner Sam at Mission Window Tint:
Mission Window Tint
(626) 328-3612
https://goo.gl/maps/DiK5Mbi4g4SKN2qq6
He carries Suntek CXP and CIR. For your Mini Cooper, I would think he could do all the windows for much better than those prices. His quality of work is great.