The motorcycle and quadratrack components (not trucks and 4WDs) of the 2014 of the so-called "Dakar" Rally will be passing through southwestern Bolivia in the second week of January.
From the website <http://www.dakar.com/dakar/2014/us/route.html> it looks as though they will come north from Salta, Argentina, on 12 January, presumably pass through Tupiza, to overnight in Uyuni. On 13 January they will go across the Salar and cross the border into Chile.
Getting the "Dakar" to come through Bolivia (even if only bikes and quads) has been heavily hyped. There is said to have been an effort to improve facilities along the route.
Even so, as well as the usual tourist flow, all the petrol-heads in Bolivia will swarm down on Uyuni and the surrounding areas, so congestion seems likely. Perhaps other posters who have been there recently can comment.
Anyway if you like to have your appreciation of stark and beautiful landscapes enhanced by the snarl of engines, here's your chance ...

