Can someone who either uses 3ds max or has some idea on scale
because i adjusted my settings in 3ds max and now my objects first come
out so small my car runs over them then i adjust the size and they come out so
big they could run over my car
In max you should set correct units. Customize -> Units Setup -> System Unit Setup. Set your preferred units and import your object back to max and if it asks then convert units. Also you can resize object in XPack. I'm no expert in max but it's the way i did it.