Dynamically-localized sensors for vehicles

Among other things, techniques are described for a system including at least one sensor, at least one sensor comprising at least one attachment configured to removably attach to an auxiliary vehicle, the auxiliary vehicle configured for attachment to a primary vehicle; at least one computer-readable medium storing computer-executable instructions; at least one first processor communicatively coupled to the at least one sensor and configured to execute the computer-executable instructions, the execution carrying out operations including: receiving data corresponding to an environment of the auxiliary vehicle from the at least one sensor; determining at least one dimension of the auxiliary vehicle and a relative position of the at least one sensor from a primary vehicle based on the environment of the auxiliary vehicle; and providing the at least one dimension and the relative position of the at least one sensor to the primary vehicle based on the at least one dimension of the auxiliary vehicle and the relative position of the at least one sensor.