The solution is called order independent transparency. It is fantastically expensive and complicated to implement with many possible but imperfect solutions, and only a couple games have ever shipped with it as far as I am aware.
The only practical approach is to sort objects by distance, so they are painted back to front. This happens by default with translucent objects, and can be turned on for particle systems, but it will not work for the faces of a single mesh. You would need to split the object into separate meshes.