...once I got the Grot riggers for my Battlewagons sorted out (see below), I also wanted some for my Trukks.
I think these Grots hanging from antennas come from the Warbiker kit (my biker models are from several editions ago, so I don't know for sure). I drilled a small hole in the bed of my Trukk model for the antenna:
...then I mounted the Grot:
I also added one to the old Wartrukk model I have:
While I don't care for the Wartrukk (the new Trukk is a waaaay nicer model) I really like the way the Grot is positioned here - hanging off the running board, just inches from being sucked under the exposed rear wheel. Very ork-y!