For Buick Regal GS I would definitely recommend BlackVue DR900X Plus. The reliability is very good The perfect fit is ideal for daily driving.

My tip: Escort MAX 360c Radar Detector for Buick Regal TourX. Very satisfied with it.

Interesting question! For Ford Focus ST it also depends on your driving style. What's your main concern?

For Buick Rainier definitely Thinkware U1000 Dash Cam. Very good quality for the price.

Anker PowerWave Mount is my recommendation for Buick Enclave. Works great!

For Toyota Crown Cobra RAD 480i Radar Detector is ideal. Good price-performance ratio.

Have also thought about WizGear Magnetic Phone Mount. How is the installation?