You see it all the time. It's usually a nice car - someone who has only been driving for a couple years and just forgets to turn them on.
If you honk or gesture at someone who is driving around with no lights on, they won't usually understand what you are getting at.
In the US, turn signals are a way to let people know which of two roads you are going to go on. So even if it's a very shallow split in the road, people will still signal.
Their point is to let other people know where you are going. There is no actual moral law saying "if you turn right X degress, you must use the right signal".
So even if the main road curves left, and a tiny road continues straight, people continuing straight onto the tiny road will sometimes signal right.
In China this isn't understood. Signalling is a mostly-forgotten automatic motion, perhaps trained during driving school but with no thought behind it. Nobody signals when merging, let alone when making a normal 90 degree turn.
People don't really communicate with each other car to car - no nod of respect for small favors. People also don't signal each other for hidden cops (there are no hidden cops)
There are no traffic cops. Somehow, things keep together anyway.
A new thing in the last 3 or 4 years is that people park anywhere. This includes busy bus stops on major ring roads. Every bike lane is now a car parking lane. You see parking cops walking around slowly with cameras about once or twice a year - they have to take pictures of the car & the parking job, because systems are so weak, without this evidence either the guilty party will use their connections to get out of it, or traffic cops will just accuse everyone in order to get bribes.
At home, the person who is going in a straight line has the right of way. Here it's the opposite - the person entering has it. So no matter how straight or consistently you are moving, it's your responsibility to deal with people jumping in. This applies to bicycles and people walking, too. Cars / bikes entering a roadway will at the least stick their nose into the stream of traffic and it's considered the traffic's responsibility to notice it and go around them.
At forks in the road, people never signal. At full on proper turns, only maybe 25% of people signal, and those that do only do it as their car is already starting to turn - not before.
If you can't turn out into traffic, at least get your nose out there and make the other guys slow down a bit.
Say your car is approaching a right turn onto a main road, with a bike lane along the edge of the road, streaming with bicycles. In the US the driver would drive at a constant, reasonable speed, then firmly step on the break to let the bikers know he was planning to stop. Bikers would feel safe to continue past him.
In china the driver will drive at a high rate of speed, then start to slow down but uncommittedly, not letting the bikers know what's going on. Bikers start to slow, but since they have the right of way, they don't stop. Car slows more, now bikers are just nosing past the front. Bikers realize they've won, and begin to speed up again, going around the car which is halfway blocking the bike lane. A mini biker traffic jam forms behind the car, which oozes out.
For normal levels of bikers (just a few) this strategy loses time for the driver, yet, they always do it. For heavy levels of bikers this might be better.
Even though you are only going to the next turnoff at the roundabout, make sure you get to the inner ring.
Don't decide where you are going to turn until you arrive at the point of decision. Then just stop in the middle of the road.
Pass your exit on the ring road? no problem, pull over and back up at high speed in the bike lane.
Parking is totally out of control in this city. People just park anywhere they want. Recently people have started parking in the dedicated bike lanes of the 2nd ring road - which was previously one of the best places to ride bikes in the city.
If the light's green, you're definitely gonna make it. No need to conserve space with the car in front of you - you can just mosey along at any speed, while people behind honk.