The disclosure includes embodiments for improving an estimate of a geographical position of an ego vehicle using wireless vehicle data of a remote vehicle. A method according to some embodiments includes determining ego estimate data based on remote GPS data and relative position data. The remote GPS data describes a geographical location of the remote vehicle. The relative position data describes a location of the ego vehicle relative to the remote vehicle as measured by onboard sensors of the remote vehicle. The ego estimate data describes the geographical location of the ego vehicle from the perspective of the remote vehicle. The method includes fusing the ego estimate data and ego GPS data to form fused data. The ego GPS data describes the geographical location of the ego vehicle from the perspective of the ego vehicle. The fused data describes the geographical location of the ego vehicle with lane-level accuracy.