2011 Buick Regal brakes problems

Tl* the contact owns a 2011 buick regal. The contact stated that the electric parking brake was in what the contact believed to be an unsafe position on the console. The contact stated that if the lever was inadvertently hit, it would cause the vehicle to come to a halt while driving at any speed. The contact believed the failure to be a design flaw that needed to be addressed.

During periods of high heat (and only high heat) after being parked in the sun, when the vehicle is being driven at highway speeds, the brake pedal will stiffen and slow the car down. The steering wheel column will violently shake, as if the calipers are stuck. Once parked, all four wheels are hot and omits a burning smell. I have replaced two tires, 2 front calipers, front brake pads, all hoses and front rotors to no avail. Brake booster and master cylinder have been checked and are not the issue.