How do modern cars regulate temperature so well?

I think everyone would agree that the OLD factory gauges read real temp. But newer cars definitely have a 'dead zone' built into them. That, and they react super slow which helps the gauge cover normal fluctuations. This keeps 'Karen' out of the dealership while the warranty is intact. Almost all gauges have some sort of non-linear response but I'm convinced newer model cars have it engineered specifically to cause non-alarming gauge needle behavior until the engine has departed the engineered operating parameters.

I too will echo the sentiment that ALL the openings from the grille to past the fan, and likely to the K frame should be as closed as possible to help create a 'wind tunnel' to help with air flow - and also that quality electric fans will beat mechanical every time. The only drawback of an electric fan is going cheap and having them stop operating. This is what makes the contour fans attractive: OEM level of engineering put into them (and if the knock off is at least half as good, it's twice as good as those parts store fans).