I thought I read somewhere that micro fusion cells were the power source of vehicles before the collapse, I am not entirely sure though. Sorry if I'm wrong

Something that takes more than a few minutes?

Then... I don't understand how the car can be considered not to be a rather longish quest. The player hasn't a clue where the tools or the parts are,
and even if they knew, and/or stumbled upon them... The locations are weeks travel apart from each other; and in one case includes combat, and even a boss fight.

Do you include having obtained the tools and the parts during one's adventure, and then being able to buy the car and have him fix it on the spot?
(I'd say that the time to acquire what's needed for the quest, should not be excluded.)

It does not take long to travel in the world of F2. Usually one does not use in-game time to calculate how long a quest is, but real time. The game could fade to black and take 2 years in-game, but that is irrelevant.

Also the main point in the cave, where you need to pass to get to certain part, is to help a town by clearing out rats. Not to actually get the part, that only takes a minute. Then sell some stuff and what not to have enough money and at last you arrive in the town where you can get the car. All in all, it takes what, 5-20 min? A long quest in F3 would have you run around the wasteland and ruins, taking a lot longer than that, real time.

If Bethesda does put a car into the game, I hope they don't mess up on the way the car works. I don't want it to be like the horse in Skyrim. Lol imagine driving over rubble and mountains with ease. It isn't realistic at all.

Also what is going to happen if you get attacked while driving? Will your car explode after it takes damage? Will you be able to run over raiders?

Yes please!

But I do NOT want enemies driving around in cars, and I want you to have to have a required repair skill to get the car

Like many I wouldnt mind something like this to dictate fast travel, a driving skill for those into traveling, I mean if we have lifelike androids, why not one nuclear powered car?

I use a mod where I have a motorcycle which needs fuelling and repairs. It's simple but a great starting point.

It's the fast travel version I use. Or by caravan.

Edit: doubles as a movable storage facility too.