Had an experience I figured was worth sharing as it left me a little spooked and perplexed!
I was recently out in Tuscon for a music festival with my close friend. We drove out from Colorado and unfortunately did so at night both ways and didn't get to enjoy the beautiful scenery along the way, but it made for easy driving. After the festival was over, we drove out to Mesa to see our friend from highschool and said our goodbyes as we prepared for the 12 hour drive home.
We left just after sunset and about 3 hours into the drive on a mountain pass (give or take around midnight) we were singing along to old 90's and early 2000's pop hits and cracking jokes and laughing so hard we had tears streaming down our faces. The moon wasn't full and we were surrounded by trees so it was really dark. As we hit a straight stretch of road on the pass, I could only see in front of the car as far as the headlights allowed and nothing behind us. There was nobody else on this road for miles but us, and I was suddenly hit with a weird feeling of uneasiness.
I had been checking my rearview mirror pretty often, as we were loaded down with camping gear and I wanted to allow faster cars to pass us, but at this point we hadn't seen anyone for nearly 30 minutes. I glanced in the mirror to the black void behind us and back ahead, and after a few seconds saw a light out of my peripheral vision and I looked up again. There was a small, dark sedan tailgating us, and really riding us close. Their driver side headlight was out and the other one was really yellowed and dim. I watched as they sped up and got right on my bumper, and I mean like less than 10 feet where it was uncomfortably close. I looked at my friend and laughed and pointed back with my thumb and said "check out this ***hole, there's plenty of room to pass us!" and when we both looked, the car was gone. Just the same darkness that had been there before and blur of tree silhouettes.
I told him what I had seen and described the car. He got goosebumps and said he had been feeling uneasy on that stretch of the pass too. Nothing else notable happened the rest of the drive, but it left a weird feeling in my gut until we made it into the next town. I have heard similar stories of ghost cars over the years but never seen it for myself until then.
I wouldn't consider it to have been necessarily scary, but it definitely left me perplexed as I have no explanation for what happened and am curious as to the history of that stretch of road (if there were any fatal accidents, etc.) Can't remember exactly the name of the pass nor the road we were on but at some point I'd like to look it up and see if there's any articles about that pass.