I finally managed to find all the tools to get the highwayman, travelled to reddings to trade in all my loot and suddenly it doesn't work anymore?`
whe I try to leave my character is walking on feet, no matter if go from the mining camp or from downtown, all ready tried to talk with NPCs but there's no usefull dialog option for this.
(I'm using the restoration patch btw)

So the car isn't in town? Unless you're in New Reno (which you aren't), this shouldn't ever happen. Or does using the car not start it up and send you to the map? I don't use "restoration" patches myself, so I don't know if it's related to that.

Not sure if I understand correctly, but if you bought the car from Smitty in Den, you leave the map by clicking on the car, not by entering the orange exit zone (if you exit by using the exit zone, you will go on foot).

Maybe you've encountered the infamous bug where the car disappears and the only thing left is its trunk? :) This shouldn't occur after all the community fixes, but who knows. If this is the case, the only solution is to load an earlier save unfortunately.

after I got my car I tried to use it, and at first didn't wanted to leave the den so I just travelled to the east sid of it, I couldn't find any car there either, I instead just left with the orange box and was traveling with the car in the map, I also encauntered a bunch of robbers and geckos on the way and I didn't see a car there either, I had to use that orange area to leave and everytime I did I was still using the car in the map except now, when I try to get out redding there's no car anymore and no I haven't been to new reno with the car.

I tried going back to the den looking arround for it there a little and later to new reno because you mentioned it and didn't find a clue. I do have i pretty good safe this time but I have a feeling it could be something else. I haven't seen any trunk anywhere so...

If you leave using the exit zone, you'll go on foot. The fact, that there was no car in the gecko encounter shows this. So you probably need to return back to Den, find the car and exit the map by using the car (not exit zone).

If you exited the map using the exit zone and yet it shows car picture in the world map window - that's probably a bug, you went on foot. You have to use the car, not exit zones.

The car is in front of Smitty's shack in Den. If you bought the car from Smitty, you can just click on the car and it will take you to the world map.If it doesn't take you to the world map, that probably means that you haven't bought the car.