Ok so when driving along all I could hear was a tapping sound , something like a wire hitting metal.
I had just installed a dual battery system, so is one of the wires hitting the body? Big no after many cable ties and cursing. Ok is it the suspension squeaking? jack up car clean and spray with silicone ,No not that either . OK is it the vinyl behind seat flimsy as it is , at this point I should explain I have a 2012 ute dx leaf sprung. After 3 months of tap tap tap and one lobotomy, I do most of my driving on dirt so I hate rattles the problem is solved. Turns out to be the air vents at back of seats they have little rubber flaps 4 of them and when you drive along flap flap flap .The faster you go the louder they get which is why I thought it was a wire or something . I took them out and put foam between the flaps and the external grate problem solved.........
Just wondering if this fix will affect the cabs ability to stop dust entering, are they just pressure vents.
Ps when I took out the vents I checked inside and there were about 6 small stones in there and some dust , the car has only done 16,000 km the bloody sill would be full after 300,000 .
So if you hear a tap flap tap this could be the culprit . Yours truly Anal Retentive