I remember a story about a car that consistently refused to start after a family went to the store to buy vanilla ice cream but it worked fine when they bought chocolate ice cream. (My apologies for any inaccuracies in my recollection of it). They had a manufacturer engineer verify it happened even.

Turned out to be an overheating issue. The chocolate ice cream was at the back of the store while the vanilla ice cream was at the front, effectively changing how much time the car had to cool down properly before attempting to start it again.