Praise be to Allah, the Lord of the World; and blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.
If the money you mentioned reaches the Nisaab (the equivalent of 85 grams of gold) and if it stays with you (in your account or else) for a whole lunar year, then you should pay its Zakah. You can consult a bank for the current price of gold to calculate how much you owe.
In fact, your intention to buy a car does not influence the rule of the obligation of Zakah.
Allah knows best.