Car theft is no laughing matter for the mafia. How, after all, can a mafioso signal that his car alone is untouchable among a thousand others? Were he to resort to a warning label, say with an M on it, so could anyone else. If he were to display somewhere on the vehicle his (less easily pirated) surname or his even more resonant nickname, he would forfeit the advantages of anonymity. One solution might be for him to leave the car unlocked, relying on the fact that in high-crime areas this would signify an intimidating lack of fear (Calzetta says that his boss left his car unlocked). A more extreme alternative is to drive a small, unassuming car, which is less likely to attract thieves; and indeed many mafiosi do own such cars. But perhaps the most theatrical solution is to buy a flashy foreign car—a black BMW, cream Mercedes, or red Range Rover (all real examples)—which transmits an unequivocal message to the thief. This gambit accounts for a notorious preference among mafiosi for showy cars, which is usually attributed only to the desire to impress.

XREF: Relates to signalling theory and costly signalling, the same logic behind conspicuous consumption and deterrent displays in economics and biology.

Diego Gambetta, The Sicilian Mafia The Busi…, loc. 922