2012 Mazda3i 5dr hatchback. Persistent issue with headlights, both low beam and high beam, as well as interior lighting and other lighting. The headlights flicker for several seconds any time the brake pedal is applied. Interior lighting also flickers when brake pedal is applied. Headlights sometimes flicker when vehicle is decelerating and no brake pedal is applied, most notable when vehicle is traveling downhill. Further, the luminosity (brightness) of the headlights visibly dims, but ds not flash, when the vehicle is parked and the brake pedal is applied. A high volume of others report the same issue, including documented complaints. These vehicles are unsafe, defective as designed, and do not conform to FMVSS No. 108. NHTSA must investigate further. Many other owners are not aware of the cause of the issue and attempt to fix it by replacing headlights, alternator, etc. Mazda was aware of issue prior to July 2013, when it issued TSB 01-019/13. This document states, ‘Some vehicles may exhibit the headlights flickering when the vehicle is decelerating (by applying the brakes) with the headlights on. This concern is caused by inadequate alternator output (controlled by the PCM) when the battery is under a heavy load. To correct the problem, the control logic of the PCM has been changed.’ This appears to be at best a temporary fix. Bommarito Mazda in Missouri required payment of $199.88 to ‘diagnose’ this problem and address it in the manner prescribed in TSB 01-019/13. This service was not covered under warranty. Service Manager M.D. claimed to have never heard of this issue before and that it would need to be diagnosed, despite being informed by the owner of the precise issue, that others reported experiencing the same issue, and that others reported the issue was addressed by reprogramming the PCM. Immediately following this service, the headlights continued to visibly dim when the vehicle is parked and the brake pedal applied.