These concepts are strictly personal opinion on what should be considered to add to the base game. I'd gladly pay a few bucks to get all this.

-Rain and storm system
-Pets can enter vehicles with you
-Add smaller catchable fish like gobbies, perch, small crustaceans.
-Underwater could use a bit more detail in terms of plants and weeds
-Put brights on vehicles.
-Allow chickens to drop eggs that you can sell like furs and fish.
-NEEDS MORE HUNTING RIFLES.
-At least one more assault rifle
- bring back healing animations. I always found these brought uniqueness to The Farcry franchise.
-Flying into birds can cause engine failure
-Have vehicles run out of gas after a LONG time of continuous driving?
-Add duck hunting?
-Add hunting tools such as a simple animal calls, Antlers for racket. Put them under utilities as a new slot.
-Personal fly creation shop for fishing