[gearheadE30]

OP, your diagnosis is right on the money. The reason the noise comes back at very low speeds is because as you approach a stop, the brakes and engine start to fight each other. It is this characteristic that results in the car creeping forward when you lift your foot off the brake. If you were to put the car into neutral before coming to a stop, my guess is that the noise would disappear. CVs tend to click when they dry out and wear over time, as the balls that transfer power will wear grooves and elongate the slots they ride in. Generally the problem is created or exacerbated by a torn boot, either on the inner or the outer CV.