The build was probably just a self-made one that wasn't saved, I loved it btw, really brings out the legoness in blockland.The vehicle looked more like a lego (pickup) truck imo, try searching for that.
I believe it was called the Brick Mobile and it was created by Blastdown. After some searching and checking the archive, I can't find it. Perhaps it was taken down or I don't recall the name.The add-on was pushed by Lord Tony and that build was created by him as well.edit: Found it!