In my experience most drivers expect 100-200. Some will ask. If you go from Pattaya to Bangkok they avoid some of the highway (to save a few bath) and then it is easy to get stuck in traffic. In those cases (even if I specifly I can pay the extra toll) I don't give any tip. 

I would probably do 2k too but 100 would be enough. It is not needed at all but at that level, every bit helps.

Nope, Nam's are fantastic and most of her drivers are single mothers. Providing the service if of the usual excellent levels then for sure round it up to 2k. it will be appreciated.

I have a trip coming up to go from Bangkok to Pattaya.  I have already booked my trip with Nams for a Camry for thb1600.  Usually I am just lazy and give them 2k and don’t want anything back.  Is that too generous?  I know it also depends on driver/driving. my question is what do you generally tip the driver?

My contribtion to this thread and an example of which option to avoid based on coments in my trip report. LOL Blame my date for this selection.