Took my "C" into the dealer yesterday for oil change, filter, and rotate wheels. Asked also why my parking brake is so sensitive that the light comes on very often.
Advisor said that after checking, my master brake cylinder was slightly low. It was topped off, no further problem.
Related, I asked why I practically have to stand on the parking brake to get it to hold, Advisor said that the brake is a small drum inside the left rear wheel only. The cable was adjusted as far as it could safely be tightened without causing the brake to drag. Still isn't what I would call a valid emergency brake. Maybe PARKING is exactly what is meant. Go figger.