At the stop sign I go through on my commute, many times cross traffic cars wait for me to get to the intersection, wave me through before they go. I suspect these drivers are either cyclists or being niceholes. It's sometimes a bit confusing cause I my natural reflex is to slow down to a pace to where I can wait for the car to go through but maintain enough momentum to go after the car passes. Granted it's usually just one car. And I always give a thank you wave.