I had similar story to the 2 tourists back in 2014. I jumped in a taxi at the airport and asked to go to Mo Chit bus station. The driver pulled away but didn't turn the meter on. I asked him to turn it on but he said, similar to the 2 tourists in this story, 'too much traffic'. Being as we weren't going fast I opened the taxi door and said 'I'm getting out'. He backed down and put the meter on. At Mo Chit I had to get my luggage out of the boot myself being as the driver stayed sat in the vehicle. Obviously I never gave him a tip.