This is the 10007th most frequent Turkish word.
bagajında
"In his/her/its luggage/trunk."
In this sentence, 'bagajında' indicates the location where old books are stored, referring specifically to the trunk of the car (possessive form of 'bagaj').
Arabasının bagajında eski kitaplar vardı.
There were old books in the trunk of his car.
Here, 'bagajında' is used to ask about the contents of a vehicle's trunk post-vacation, emphasizing possession and location intimately connected.
Tatilde götürdüğün eşyalar bagajında kaldı mı?
Did the items you took on vacation remain in your trunk?
In this case, 'bagajında' refers to a compartment typically used for storing items on a bicycle owned by a friend.