When I was a young rider in Cheshire, with the South Lancashire Road Club, it was just "oil". Down here in North Herts, it's "car up" or "car down". I agree with those who say that up and down are confusing, not least because, in a road race, the terms are used the other way round.
So, assuming that the road was not closed, the break that was up could be passed by the car that was down just before the group that was down was overtaken by the car that was up.
You figure it out.