One reason why cars aren’t in the game (yet), is because the devs were (are) afraid that it would ruin the atmosphere, because players would just rush past everything.
I personally think that it would actually add something to immersion and atmosphere.
Imagine:
You are on long drive in a dark and rainy night. But you forgot to fuel your car, so you become stranded. You then make your way to a nearby farm and get some fuel. On the way back to your car you see some lights moving in the forest. You take out your binoculars and check what’s going on. It’s a group of hunters. You hide in the bushes until they have gone past, then you run up to your car, refuel it and continue your drive, just in time before the hunters come back.
You are driving around on a sunny day when you are suddenly ambushed by a group of runners. You careen of the road and flip your car. Still a bit disoriented, you suddenly have to fight for you life.
You are scouting out a town and see that two tanks are guarding the it. So you drive back to your hideout and load your granatgevär into the trunk. You drive into town and park your car near the tanks. You get you granatgevär and start the fight. After the two tanks are finally defeated, your health aswell as your supplies are depleted. But the fighting attracted a lot of machines. So you run back to the car and race through the streets, dodging machines. You breath a sigh of relieve as you are finally back on the open road and see the robots getting smaller and smaller in the rearview mirror.
You are driving, and suddenly see blue flashes ahead. You get out of the car and take out your binoculars. You see a crashed military convoy ahead, the emergency lights of one of the escort vehicles still flashing through the night. You sneak up with your sniper rifle, taking out the two runners guarding it. After you cleared the road and took what useful supplies were left, you continue your drive, wondering what happened to the soldiers as you pass by the wrecks.
I don’t know, sounds pretty atmospheric to me.