First of all - BIG props for masterful audio design, I was consistently holding a brick clenched with my anus muscles the whole time. The silent drums in the background are a really nice touch. Leaving the radio turned on while you get out of the car - man, that was so bad for my nerves. I also noticed some other details, like crunching sounds and then a loud "Moo" (shouldn't it be in reverse?).
The graphics are serviceable, I actually really dig the red mist covering everything, that's really neat, adds to the nervouslness. Dunno if the track is randomly generated or you just have multiple maps, but it's also a nice touch, along with some random landmarks along the road. The wendigo running across kinda got me the first time, the "standing in the middle of the road" monster was too on the nose. Loved that the box starts shaking, at first I thought it was the physics, until I started paying attention. Only wish I could've opened it...
In general you have a lot of tiny little details that really bring the game to life. It's awesome. I'm no horror fan and I'm easily spooked, but I really liked the experience.
People have already mentioned, but there are a lot of bugs. Mouse not being properly bound to the window, bad respawn after monster death. I will mention only one thing - after a couple of runs I started figuring out the scripting for the encounters, so the spooks were not as effective (I was still nervous due to ambient sounds, that's how effective they are).
Anyway. It's a really, really cool game you have here. Needs a lot of polish, obviously, but I hope you stick to it and don't abandon it.