spawning pedestrian props and vehicle mods by themselves?

[DAMND]

trainers can spawn almost any small prop in the game, even some that are relatively huge

 

they can also spawn pedestrian props and vehicle mods if you've already spawned the corresponding ped or vehicle

 

so is there any way to spawn these things by themselves? if so then we could attach them to pedestrian bones with simple native trainer or vehicle parts with menyoo and make some fun vehicle mashups

 

but I haven't been able to make any file names or inputs work when trying to spawn these. any ideas? or is this something that can't be done for some reason?