Nomad remains

[QuestionZ2]

I'm having trouble getting nomad fighter remains without having to buy them. Sure, I could buy them but that's no fun and besides, there has to be an in-game way that the sellers got their hands on them.

I want to know how.

I tried killing nomad fighters-form light to VHF class, flying indie and also with NPC missions, all they drop is alien organisms, of no use to me.
The gunboats have only been the one class that I have been able to farm remains from but I need all other kinds too.
Before going and trying for Battleship remains, I wish to be sure whether they drop them or are glitches like fighters.
Also, a little light on the best place to farm each type would be much appreciated.