when quite drunk in the back of a car "trancing out" involves raving as hard as possible to house/trance/techno/drum & bass etc. often trance out battles occur to see who is the most drunk/off thier face.
"let's trance out to this tune...annnnnnnnnnnnnnnnd... RAVE!"
much like in the situation where you would say "balls" you can instead replace this word with "balt". Often shouted by the Southern British in an nightclub where the girl they are trying to get with rejects them or an unbelievable fuck up has occurred.