@John Cumner asked a good question about tipping expectations in Vietnam. In general, tipping is not at all expected. Local people and expats do not tip for routine things like having a meal or even drinking at a bar. The only exception is if you hire some service, for example hiring a driver for an extended period or booking a tour guide. In this case feel free to tip if the guide provided a good experience.

Can anyone recommend the best scooter rental shop in da nang, arriving tonight and will need one for 10 days, thanks