I don't think many have driven to the South Pole or across Antarctica, but it was certainly done by the Fuchs-Hillary expedition in 1957 or so. The 2007 looks interesting, one of their goals seems to be to supply the South Pole station by land, saving all the air costs.
The Russians drive all over the place supplying their "Pole of Inaccessibility".
Well known bore Ranulph Fiennes was going to spend eight million dollars or so driving Cats in winter across the Pole in order to raise two million dollars. A fine effort of egotistical fund raising that failed.