How can police track me down if im using wireless/phone?

I not many police are doing this (but some do), it's normally other law enforcement such as FBI CIA etc.. it what they call wireless triangulation. Wireless triangulation is a method of determining the location of wireless nodes using IEEE 802.11 standards. It is normally implemented by measuring the RSSI signals strength. Again this is usually done on someone who has done something very wrong but there are ways around it such as use a satellite phone.