I'm not the designer on those. I will probably buy them and modify them for my use. I know a little Solidworks and OnShape but I'm learning Fusion360.
I've also found I can use Tinkercad for quite a bit of .stl editing pretty easily.
My build thread I've been working on exterior stuff...
I also kind of love the TRX4 Sport body so I have been looking at this myself. I did find a set of files for a TRX4 Bronco interior that is only the front part. I'm thinking I can modify the files to make it work.
I also think for it to work right the battery mount has to be either swapped for...