As you can see, the entire experience made quite an impression on me. I'll probably still remember it into my Alzheimer's.
In the context of reading Buick 8 as a stand alone novel, there is not much explanation, but if you link it to The Dark Tower and treat the Buick as a connection to Roland's world (I like to think it opens up into that horrible, monstrous valley they ride over when they are trapped in Blane the Mono) then it makes more sense. I read King when I was younger and then avoided him throughout the late eighties and nineties but I recently read Buick 8 and the Dark Tower series and really enjoyed them, so I think I will go back to some of the works I have missed over the years.