Numerous challenges are faced when reconstructing bullet trajectories fired at a vehicle because of the irregular surfaces of the vehicle, impacts through open windows, and deflections. Creating and using baselines around a vehicle allows for measuring trajectory angles in relation to each other, the vehicle itself, and the angle of declination.
Bullet Trajectory Reconstruction on Vehicles
Vivona, B.; Gaspari, M. Bullet Trajectory Reconstruction on Vehicles. J. For. Ident. 2009, 59 (1), 51-58.