I hope the car has a VIP car fleet with a toilet, then there will be nothing to complain about.

I traveled with my wife from Saigon to Danang. Everything was fine. The bus was new and comfortable. The staff didn't speak English, so we had to use Google Translate. They showed us where toilets were and where to eat. The bus stopped 4 times within our 16-hour trip. We arrived 3 hours earlier than expected. Authentic experience :). The main problem was the company changed our pick up point. They were calling us a whole morning to inform about it but we couldn't understand Vietnamese. The manager in our hotel helped us.