It only takes a few minutes to set up such a situation. Find a quite stretch of road, even close it for a short time. James & Richard did that fine on their own without worrying too much about the jam that ensued. No one said anything about safety equipment, not much use anyway. Right spot where they can be seen from almost opposite. Oooh nice waterfall, perfect. Useful to grab the close up of tyre on edge. Get the camera crews in position, turn one vehicle around and 'action'. Vehicle was a new Toyota Sequoia, too rich to be a typical local. Metal-tech the guys who built the FJ and ran vehicle support said they were given a brand new 2010 Hilux to use, they even ripped the plastic covers off the seats. Simple conclusion, the Sequoia (potentially a $50k car) was also a crew car.
I'm not the only one to think so:
http://forum.ih8mud.com/trails-events-expeditions/345621-bbc-top-gear-chile-bolivia-special.html
Not that any of this matters as overall I thought it was a great 'show'.
And you're still patronis(z)ing. I've studied and worked in video and TV media for over 15 years.