In the context of vehicle-positioning applications, Global Navigation Satellite Systems (GNSSs) have remarkable role. However, these applications have very strict safety requirements, thus needing an improvement in the performance of such positioning systems. This necessity has led to the development of Cooperative Positioning methods, also thanks to the recent rise of Vehicle-To-Vehicle (V2V) communication. The aim of such methods is in fact to improve both the accuracy and precision of the stand-alone positioning system by exploiting the exchange of relative ranging information by a network of vehicles. Moreover, in spite of the fact that the positioning problem is non-linear (i.e. trilateration), many solutions approach it by means of linearization (i.e.