Both antennas are for AM and FM. This is the "diversity" antenna system which used two antennas with the stock Nissan head unit, one vertical (fender) and one horizontal (glass). The stock head unit could switch between antennas for best reception, but it only really helped in urban areas where signals bounce off buildings, causing what is known as multipath interference.
Most FM stations transmit in both vertical and horizontal polarization so the hatch antenna should work, at least to some degree. Try it and see, you're not going to hurt anything. Let us know how it works.
Last edited by SE-RMonkey
on 2014-01-16
at 15-49-21.