Iīd like to add my 2 cents here. They originate from the time when I was very young, lived in a small village without public transport, and did a lot of hitchhiking.
Iīd like to point out that the family I lived with was well-known in the area, and it was typical for the village inhabitants to pick up hitchhiking youngsters because they did the same before they got their own driving licence. However, there were times and places where I joined the cars of complete strangers.
I also spoke about my experiences with the Dom who later introduced me to the lifestyle together with his lady, which was a great help for me.

First of all, donīt hitch-hike unless you really have to, of course :-)
1. Donīt tell where you want to go - first ask where the driver is heading. If that is your direction, you can join. This way you avoid to be captured by some guy who will just tell you what you want to hear, and then go somewhere else (like into the next dark wood, yes).
2. Upon entering the car, do NOT show fear of contact! Look him in the eye, speak clearly, donīt twitch or pull back your hand if it happens to touch his when you buckle your seat bealt.
3. This piece of advice came from a guy who used to do a lot of hitch-hiking himself. The ride with him proved to be the most entertaining :-) He said, do not answer any questions the driver asks you honestly. It is not his business what your name or occupation or place of living is. Tell him fairy tales. If youīre not good at stand-up lies, prepare a story that you can tell at such occasions.
4. Contrary to what we are told so often: Donīt cover your whole body with clothes. I tested various clothing styles and found that I got the really obtrusive come-ons when I dressed the most decently. This does not mean you should make yourself look cheap! Just show you are aware of your body. The aforementioned Dom explained to me that a woman who obviously is aware of her body and the reactions it may cause means TROUBLE if someone is trying to take advantage of her. Meaning she will know what to expect, and will have means to fight back.
5. Do NOT carry a weapon (e.g. knife) unless you REALLY know how to use it! A potential attacker will very likely take it from you and use it against you. Pepper spray might be a better thing, but it could be problematic if used in a closed space like a car.
6. If you feel uncomfortable in any way with the person whose car you are in, GET OUT, if need be at the next gas station!
7. Make sure your driver knows you are expected within a certain timeframe, and if you donīt turn up, people will be looking for you. (This is even easier today, as everybody has a mobile... my hitchhiking times were before the mobile era).
8. Never ever let the guy take you to your doorstep, NO MATTER how trustworthy he might appear! Get out of the car a few streets away from the place where you are really going, and MAKE SURE (!) that he drives away before you go in your planned direction.
9. If you get any indecent offers (and you will get them - many men seem to believe if a girl gets a ride, she will be willing to give a "ride" in return...), decline firmly but politely. If he does not give up his attempts, GET OUT at the next occasion!
10. Avoid at all costs to appear scared. It gives them the feeling they are in control.
11. And here is one for the smart-asses who tell girls only to join cars where the driver is a woman, or where a woman is also in the car: That doesnīt happen.
I have taken approximately 200 hitchhiking rides, and the ONLY time a woman driver stopped for me was because she mistook me for her daughter.
As for the couples in cars: The guys usually look friendly, the ladies beside them look usually VERY poisonous. Especially if you are younger and prettier than themselves.

As for denuseriīs former post: I think some of those precautions should be taken by vanilla girls meeting vanilla guys. Itīs not like the weirdos were to be found only among the BDSM folks...

Kind regards
Arria