Front seat politics

Situation: 

One shiny, white, 4x4 NGO vehicle with Cambodian driver to take 3 people from the guest house they are staying in to a rural hospital where they are conducting training

Travellers:

J -  a 56 year old English female nurse & line manager to R, works for NGO with lots of USAID $$$ & shiny vehicles, owns a moto

R - a 29-35 year old (age dependent on who he is talking to!) Cambodian male nurse works for above NGO in a technical officer position & owns a moto.

Me - a 39 year old English female doctor, volunteer with another NGO that has no shiny vehicles & borrows a bicycle, basically a stow away

Question: 

Who does local culture & protocol dictate should sit in the front seat?

Variables to consider:

Gender, age, nationality, job title, social status, bank balance....

Answer:

R walked but his bag travelled in style in the front seat!

And that pretty much sums it all up.