Here it is,
If my memory served me correctly creating the physics.jms was not much of a challenge. You place your spheres where you want them, export the file and whoolla! a physics file. However when I do this I get an error:
ERROR failed to create intermediate model

I'm thinking, hmmm thats strange I wonder what went wrong. Playing around longer, I find out if I leave my vehicle model intact with the spheres I can export the file, bypass the error and create my physics file. Now when I try to open the file inside guerilla the program force quits.

Doing more trial and error I import physics from an existing vehicle inside my model. Export the physics and amazingly the file exports and can be opened within guerilla. I'm thinking thats odd and delete the imported spheres except a few that I want to keep, position them where I want them and run the export again but once again guerilla crashes.

With plenty more trial and error I manage to get a half ass physics created and opened inside guerilla with some imported spheres. Within guerilla I try to resize the spheres and once that happens the program crashes. I'm very confused. Anyone run into anything like this before. Its very odd.