For there to be cars, the map needs to be much larger and the cars shouldn't drive too fast. I am pretty certain there will be a larger map for Fallout 4. The driving of a car should not feel anything like in Borderlands or how it looks like in Rage. You are not meant to race with them. The speed would be faster than running speed, but not so slow they're useless. They wouldn't be useless though, due to their big inventory space.
I am thinking if we were to see cars, Fallout 4 should take place in Detroit aka Motor City. A reason as to why there are operational vehicles.
Also, one thing:
Inconsistent with previous Fallout games, where vehicles were stated to run on electric engines drawing power from on-board batteries, the cars were supposedly nuclear powered, with a small reactor to the rear of the vehicle.
So, the cars originally ran on batteries, charged with nuclear power, and not a reactor at the back. Cool as the idea is though, it's not really that good when you get shot at or crash into things. Anyways.
Battery-powered vehicles:http://images3.wikia.nocookie.net/__cb20090514220427/fallout/images/thumb/7/7b/Fo1_Corvega_Composite.png/830px-Fo1_Corvega_Composite.png
- Faster than the average car (can be upgraded)
- More fragile than the average car (can be upgraded)
- Runs of batteries, medium consumption (can be upgraded)
- Doesn't blow up when damaged.
- Bad when it comes to off-road, stick to the roads (what's left of them) and flat terrain (cannot be upgraded to off-road better)
- Not a good idea to go road killing with (will damage you and your car, aswell as slowing you down alot, depending on what kind of critter you hit)
- Cannot mount guns (or what do you think?)
- Below average trunk space.
http://images3.wikia.nocookie.net/__cb20091025220204/fallout/images/thumb/5/56/HighwaymanRender.png/830px-HighwaymanRender.png
- Unique car.
- Faster than the average car (can be upgraded to be the fastest car)
- Average damage resistance (can be upgraded)
- Runs on batteries, medium consumption (can be upgraded)
- Doesn't blow up when damaged.
- Average when it comes to off-road, but can be upgraded. Still, roads and flat terrain works the best.
- "Medium-effective" to go road killing with, it's somewhat sturdier than the Corvega.
- Can be upgraded to mount a small to medium gun (or?)
- Huge trunk space.
- Can take 5 passengers instead of 1.
Reactor-powered vehicles:http://fallout.wikia.com/wiki/Highway_patrol_car
- The fastest car unmodded (can be upgraded to even faster, at the cost of vehicle control)
- Average damage resistance (can be upgraded)
- Uses a nuclear reactor, doesn't have to be refueled (or you refuel it much less often)
- Risk of exploding after recieving a lot of damage (stupid idea) but can be upgraded to be more stable so it won't explode, but instead an unrepaired car will leak a lot of radiation.
- Average when it comes to off-road but can be upgraded (but combining this with the high speed upgrade can have dire consequences)
- About as sturdy as the Highwayman when it comes to road killing, but it becomes a huge danger at top speed if the critter isn't squishy enough.
- Can be upgraded to mount a small to medium gun (or?)
- Average trunk space.
http://images4.wikia.nocookie.net/__cb20110302094515/fallout/images/thumb/0/0b/ChryslusAd2.png/830px-ChryslusAd2.png
- A bit slower than its Corvega predecessor originally (because I think the first one looks more streamlined), but can be upgraded to be faster than a fully upgraded Corvega original)
- Below average damage resistance, but still more than the original Corvega (can be upgraded)
- Uses a nuclear reactor, doesn't have to be refueled (or you refuel it much less often)
- Risk of exploding after recieving a lot of damage (stupid idea) but can be upgraded to be more stable so it won't explode, but instead an unrepaired car will leak a lot of radiation.
- Below average when it comes to off-road, stick to roads and flat terrain. It is a sports car after all. (cannot be upgraded to off-road better)
- Road killing... still a bad idea when your car has an active nuclear reactor... But well, it's sturdy design makes it a bit better for it than the original Corvega, but still not ideal for it.
- Cannot mount guns (or what do you think?)
- Above average trunk space.
http://images2.wikia.nocookie.net/__cb20110302094421/fallout/images/thumb/b/ba/ChryslusAd1.png/830px-ChryslusAd1.png
- Being streamlined and reactor-powered, it's faster than the other Corvegas (can also be upgraded)
- A bit fragile though, below the V8 (can be upgraded)
- Uses a nuclear reactor, doesn't have to be refueled (or you refuel it much less often)
- Risk of exploding after recieving a lot of damage (stupid idea) but can be upgraded to be more stable so it won't explode, but instead an unrepaired car will leak a lot of radiation.
- Not good to go off-roading with (cannot be upgraded to off-road better)
- Road killing is also a bad idea, not as sturdy as the V8 here.
- Cannot mount guns (or what do you think?)
- Average trunk space.
http://images1.wikia.nocookie.net/__cb20090806152915/fallout/images/f/f3/CorvegaMZ.png
- Errr, pretty much the same as the V8 Corvega.
- A bit slower due to weight
- Ability to take 5 passengers instead of 1.
- Bigger trunk space.
http://fallout.wikia.com/wiki/Pickup_truck
- The slowest car in the game, I'd say, though of course faster than running.
- It's much sturdier than the sports cars.
- Uses a nuclear reactor, doesn't have to be refueled (or you refuel it much less often)
- Risk of exploding after recieving a lot of damage (stupid idea) but can be upgraded to be more stable so it won't explode, but instead an unrepaired car will leak a lot of radiation.
- Is pretty good at off-roading (and can be upgraded to be even better)
- Road killing is not a good idea due to its reactor being in front, but it can be upgraded with a snow plow for this purpose (and clearing debris on the roads)
- Can be upgraded to mount small to big guns in the pickup's bed, at the cost of storage space. Can also be upgraded to take more passengers, also at cost of storage space.
- Huge storage space in the back, but can be smaller to make room for upgrades.
Others:http://fallout.wikia.com/wiki/Motorcycle
- Pretty fast, though not the fastest (can be upgraded)
- Very weak, a bullet to the front tire and it'll send you flying (can be upgraded)
- Do not know what it's powered of. It looks like it runs on gas, it has an exhaust pipe and a gas tank. But on the Wiki, there's a note that suggests it runs of batteries. So, it's probably battery driven.
- Therefore it doesn't blow up, but needs refueling/recharging.
- This vehicle is the best choice at going off-road.
- Road killing is not that good of an idea, you will probably wreck the bike and yourself by crashing into people with it.
- Cannot mount guns (that'd be ridiculous on a bike)
- No additional storage space.
- It's greatest pro is how fast and agile it is compared to its size. It will be able to drive on roads that cars wouldn't be able to drive on due to debris, wrecked cars and such.
Probably many other cars, like some kind of http://www.richardsjohnson.net/sitebuildercontent/sitebuilderpictures/jeep.jpg. Maybe someone wants a http://images2.wikia.nocookie.net/__cb20110326201413/fallout/images/thumb/7/76/FNV_Flatbed_truck.png/830px-FNV_Flatbed_truck.png.
Also, the vehicles can be targeted in VATS. If enemies drives them, like a motorized raider gang, then you can target either of the four wheels (to tactically make the vehicle veer into his friends), the driver, any other passanger (someone who is most likely shooting at you), the reactor at the back, or if it's a battery car, the front (I assume it's located at the front), aswell as the doors if you wan to. Or the mounted weapon, if there is one.