Designer Jan Charvát creates the free font Velodroma:

Velodroma is new display sans serif, probably one of the widest typefaces ever made. But the widest is not the only thing you get. You get regular and wide too and in one font, so you can combine them together. And if you do not want to do it by yourself the typeface will do it for you through stylistic sets.

Be aware that this works only in Indesign by this time, but all the characters are available through wide and superwide styles in other apps too. There are also stylistc sets which will do pseudorandom spaces in between your letters so you can go really crazy with all the stylistic sets combined together.