It does "appear" to be a bullet/projectile type damage. That damage requires velocity to penetrate the metal, especially at an angle. If done my a tool or machine-type object, usually there will be some evidence at the point of entry, of the "exit" of the tool/machine, even the slightest scrape/bend on the lip in the opposite direction, AND there will be greater adjacent damage. To be sure, look for 1) what stopped it, 2) the actual bullet/projectile, will in this case be inside the trunk. You can get a trajectory by inserting a long stick, approximating the angle from outside, into the hole, and looking for a sign of impact, even a deflection. The outside metal will have slowed the bullet enough to only bounce of an inside hard surface, and it could be ANYWHERE inside there. An actual inspection would be required to be sure.