Question about cell modification

[wet geyser]

I was wondering if I would be able to easily modify a specific cell (Rosewood Firestation) for future runs and have certain things spawn in there. For example; a 100% guaranteed fire axe or a Chevalier D6 waiting for me in the parking lot

[modern vine]

afaik you can't without mods or you can spawn them with debug enabled if you want that makes your life mod-less and easier!
All you can do is bump up the loot settings for an axe to spawn in sandbox and bump up the car spawns.