Is zakat obligatory on a car that was purchased with a portion of an amount that had been saved for an unspecified period?

Zakat is obligatory on the aforementioned amount annually if it reaches the nisab and a hawl (full lunar year) passes over it, whether by itself or by adding it to other money or trade goods. Precaution is necessary in this regard. As for the car, if it is for personal use and ownership, there is no zakat on it. But if it is for trade, then zakat is obligatory on it.