These methods assume (a) the perp has the laptop on and is still in Sosua (b) the MAC address hasn't been changed (c) you have the equipment, time, and are a little insane. A couple options:
1) If you knew the preferred network list configured on the wireless interface and the respective network keys, you could configure a "honeypot" access point, hook it up to a high power transmitter (directional antenna for bonus points), drive around Sosua, and as soon as the laptop associated with the network, keep sending it packets, and you could follow it back to it's physical location using the power levels of the adapter. Even if he didn't have the MAC address, this method would work.
2) You could configure your laptop for various hot spots in Sosua, and knowing the network keys and MAC address of the adapter, it would be fairly easy to find the laptop as long as it was sending data on the network. You could just wait for it to send data and look for the MAC address in the packets or just map the network every so often and look for the MAC address in the list of recognized hosts.
There's a few tools available for porking around with WLANs to make this really easy.