<human>: I've been having trouble with my car lately. What's the most common cause of this kind of problem?
<bot>: The most common cause of problems with a car is usually related to the engine, such as an issue with the fuel system or a mechanical failure in the engine itself. It could also be due to a faulty electrical component, like the battery or alternator, which can lead to a variety of symptoms ranging from decreased performance and starting issues to complete breakdowns.