the only part of the m500 that is wireless is the datalogging feature. the rest of the unit/o2 hooks up the same as the 250/300 series.
basically, it saves you fom plugging the laptop into the unit. theres a small antenea that connects wireless-ly to the usb antenea on your laptop.
the o2 is still hard-wired to the ecu and the unit. and you will still have to install the supplied resistor if you want to mimic narrowband. Or, leave your stock o2 in place, and add a new bung for the wideband and use it as a meter, not a reading, only.