A system may include in-vehicle components arranged symmetrically within and delimiting boundaries of a vehicle interior; and a processor programmed to identify signal strength information indicative of distance of a personal device from wireless transceivers of each of the in-vehicle components; and compute, using the signal strength information, a quadrant and diagonal sector including a location of the personal device, and whether the location is within the vehicle interior. A method may include identifying a quadrant of a vehicle including a location of a personal device by comparing signal strength information of pairs of wireless transceivers in adjacent quadrants to signal strength information of wireless transceivers opposite the pairs; and determining a diagonal sector including the location by comparing the signal strength information from the wireless transceiver of the quadrant to the signal strength information from the wireless transceiver in a diagonally-opposite quadrant.