Sry for bumpz0re...
Myself I've gotten three variations of BSM's to work in SA (PS2 no spawn/armax).
I've gotten an NRG:
#Stuck in the ground
#Stuck in a rail
#Stuck between (light)pole and wall
The stuck in ground and between pole and wall I've gotten about 55ft (17m) height of.
If you can get an NRG stuck in the ground and rails on PS2 legit, you should be allowed to spawn it stuck in ground and rails on PC.
*will post pics of the squeeze version later on*
Thx to RAD for the squeeze between pole and wall version