Hobbs never smiles until the end of the movie.
Brian O'Conner: We just went from the middle of the "most wanted" list to the very top.
Throughout the entire chase scene at the end, the vault creates sparks on the road. Yet when they get to the bridge, no sparks appear. This cannot be due to the vault being empty at this point, as the vault itself is 10 tonnes, as mentioned earlier in the film.