My point is that you can report the driver (not just for the route s/he took, but also potential meter tampering - which can be easily figured out based on the route) if you have a picture of the ID (+license plate if you wish to make an extra effort). The threat that you can report them is probably more than sufficient to deter, so that you don't have to actually report them. In the last few decades, I've seen huge improvement in China of the culture of customer service and how seriously companies there deal with complaints (local Chinese seem to complain a lot more than those of us who mostly live elsewhere).