Type of nightmare where one is paralysed and unable to move. In its most horrifying form, one is incarcerated on one's back inside a long pipe; light (usually coloured, e.g. cyan, yellow or magenta) may be seen in the distance at one end of the pipe, but the pipe itself is black.
Dizzy coach nightmares are usually accompanied by an echoing low-pitched mechanical droning sound, similar to a recording of a cement mixer subjected to excessive reverb.
I had a terrifying dizzy coach nightmare last night.