This is the 6545th most frequent Turkish word.
aracını
"Aracını" means "your vehicle" in English.
In this sentence, 'aracını' (translated as 'his vehicle') is the possessive form of 'araç' with a third-person singular possessive suffix (-ı) and accusative case marker (-nı).
Ahmet garajdan aracını çıkardı.
Ahmet took his vehicle out of the garage.
Here, 'aracını' is used similarly to refer to 'her vehicle', also with the possessive suffix and accusative case, indicating it as the object of the action.
Selin aracını tamir etmeye götürdü.
Selin took her vehicle to be repaired.
In this example, 'aracını' refers to 'her vehicle', used in the accusative case to highlight that it was 'used' for transporting her.