BTW, because I thought that image of the back of the van looked suspiciously photoshopped, I went back to the episode (which I still had recorded) and looked.
There is indeed something on the back of the van as it pulls into the gas station, it's the right shape, but I don't have good enough resolution to say for certain it is a Dharma symbol. I think it is, though.
Which brings up a question a friend asked -- who owned the van? Was that Hurley's friend's van -- and if so, why was *he* driving a van with a Dharma symbol -- or Hurley's?