Hanumanji's flag signifies sense control and mind control that gives victory to the higher nature over the lower nature.
Arjuna's Chariot bursts into flames at the conclusion of the war.
After the war was over Sri Krishna asked Arjuna to take down the Gandiva and get off from the Chariot, as this is for his good only. Arjuna did as he was directed. After this lord Sri Krishna abandoned the reins of the steeds and dismounted himself from the chariot as well. After Sri Krishna had dismounted from that chariot, lord Hanuman that topped the mantle of Arjuna's vehicle, disappeared there and then. The top of the vehicle, which had before been burnt by Drona and Karna with their celestial weapons, the chariot with its quick pairs of steeds, yoke, and shaft, fell down, and reduced to ashes. Arjuna was amazed with this sight and with folded hands he asked Sri Krishna on why the chariot has been consumed by fire. Vasudeva said that the chariot was consumed by diverse kinds of weapons. It was because He had sat upon it during battle that it did not fall into pieces, previously consumed by the energy of brahmastra, it has been reduced to ashes upon his abandoning it.