Date: 25+ years old.
Country of origin: Unknown, predominantly western cast.
The man of a family disappears suddenly, without a trace. The wife believes he bailed for some reason. Every year, on the date of his vanishing, she mysteriously receives a flower from someone, she thinks it's his husband taunting her.
She tells all this to a man she knows.
Later, through flashbacks, we learn what really happened to the husbad. He was hitchhiking, a guy picked him up. They talked, then the driver unexpectedly floored the brakes, causing his passenger to hit his head on the dashboard, losing consciousness. The driver takes his IDs, places his own IDs on the husband and dumps the body and the car in a river maybe. The authorities believe the driver died in the accident, not the husband.
The acquaintance, the wife tells her story to, turns out to be the driver.
It's not The Girl with the Dragon Tattoo.