Correct. Either they've got their switch on "off" instead of "auto", or they don't have auto headlights. Or there is a problem with the system.

Yes, that is a blanket statement. If there is an “auto” setting for the headlights, headlights and taillights will come on when it’s dark if they are set to “auto”. For any car made for the US market in the last 20 years.

I don't know how it is confusing. When the headlights are on, the taillights are on. If your headlight switch is in auto mode, the headlights and taillights will come on when it gets dark out. Any other time the headlight bulbs are illuminated without the taillights being on is because of DRLs. DRLs are to increase the visibility of your car during the daytime and are not intended for use at night or any other time the headlights are needed (because headlights also turn on the taillights). If your actual headlights are on and the taillights aren't, there is a problem somewhere.

There is a light sensor on your dashboard. When it gets dark enough, because it's dusk, or your drive into a tunnel, or there's a solar eclipse, it will automatically turn on the headlights (and taillights), if the switch is set to auto. When you drive out of the tunnel or the eclipse is over, the lights will turn off. Do you have a lot of stuff piled on the dashboard of your car? Maybe you have an electrical problem. When you checked the taillights, did you have the parking brake engaged?

Often times, when it rains, it's also dark enough to trigger the automatic headlights. But not always. Some cars turn on the headlights (and tailights) when the wipers are on, if the switch is set to auto. Yours may not.

Yes it does. There is not a car made for this country where the headlights would automatically turn on without turning on the taillights. It's federal law. The headlight bulbs might illuminate without the taillights turning on because of DRLs, but if you turn on the headlights or have the switch set to auto, the taillights will come on. Some manufacturers might add additional features like headlights (and therefore the taillights) come on when the wipers are on, but the auto switch, if it turns on the headlights, will also turn on the taillights. If it doesn't, then it's not controlling the headlights, it's controlling something else.

My car does the same thing.

No kidding.

You're using the word headlights to mean just the headlight bulbs. Others are using the term headlights with the understanding that when you turn the headlights on the taillights also come on. People that drive around in the dark and rain with their headlights off are stupid, I agree. DRLs are sometimes the problem, because they trun the headlight bulbs on without turning the taillights on. But if your headlight switch is in auto, the taillights will come on when the headlights (the actual headlights, not the DRLs) come on. People are saying to use the auto setting if it's available, and I'm agreeing with them.

Here is a link to a pdf of the owners manual for your car. Page 213 describes the operation of the lights. If you put the switch in auto the taillights will come on. If they don't in your vehicle, then you should get it serviced because there is a problem.

What kind of car do you have?

Headlights are always tied to taillights. If the headlights are on the taillights are on. Headlights and DRLs are two different things, though some DRLs use the same bulbs as the headlights, just dimmer.

There is no car in the country that turns the headlights on and doesn't also turn the tail lights on. It's federal law for car makers that the two are linked. When you turn your headlights on, either manually or they come on at dark, the tail lights also come on. DRLs and headlights are two different things, but DRLs may use the headlight bulbs.

When people say headlights they mean the taillights too. When you turn headlights on, the taillights come on. If they mean just the lights in the front, they’ll say DRLs or running lights or something.

I highly doubt that. There’s no point in having DRLs tied to a switch. They’re DAYTIME running lights. The DRLs are just dimmed versions of headlights (and without the taillights) in most cars. If your headlight switch is in auto, the DRLs should be on until it gets dark, then the headlights (maybe the same lights as the DRLs) and taillights will come on after dark. Next time your switch is in auto, the car is running, and it’s dark out, check to see if your taillights are on.

How did you buy a car without registering it at the time of purchase? Was it a private purchase and you just did a title transfer? If you take your plate and paperwork to a notary or title transfer place, they can do it. You can’t do it yourself on the web.

You were not at a PA toll booth if there was someone in it taking cash. PA hasn't had cash booths since covid hit.