My car's low beam stopped working on the way back from Goa. Didnt even think of stopping and getting it fixed or calling M.A.S.S or whatever. I just slowed down a bit (it was raining heavily anyway) and carried on.
I would think a "breakdown" situation is when your headlights are not working at all.
EDIT: Its not all bad, you know. Just remembered this story of how M.A.S.S really helps ->
http://www.team-bhp.com/forum/street...est-night.html (GEARSHIFT CAME OFF! Inside forest-At night!)