Distress signal for a broken-down car

FLARE

5-letter answer

A "flare" is a bright, attention-grabbing light often used as an emergency signal, which fits the idea of a distress call from a stranded vehicle. The clue plays on the literal meaning—drivers might use road flares to alert others when their car breaks down—while keeping it straightforward. There’s no hidden wordplay here, just a direct connection between the situation and the tool commonly associated with it.