I had a problem identical to this, although mine is only a 2004 1.0 5dr, after several weeks of grey hair pulling and swearing...
Look into your spare wheel well in the boot, and the jack should be resting in a little groove on the floor next to the wheel
There should be a 'rubber band' with two metal clips keeping the jack tight to the floor (to stop it vibrating) i'l bet its broken off, the rubber in them perishes easily...
I went to 4 different breakers, at least 10 micras checked and the rubber was broken on them all
Went to the Nissan dealer, they had the rubber in stock, parts guy said he sells a few of them which also makes me think its a common problem (cost €4.00)
I put the new rubber on and no more lower rev range vibration... the jack sits right over where the back box is hung off the body so this is most likely where the resonance is occuring....
I dont know if the 160 even has a spare tire but i hope this was some help to you mate (Y)
