If the police is not including the car in the items to be recovered under section 406 IPC, wait for the charge sheet to be filed by the police before the court and after knowing the details you may submit a petition as a defacto complainant ti direct the police to reinvestigate the case and to include the car in the items to be recovered on the basis of the documentary evidences provided by you.
Your advocate will be able to guide you with the procedures to be observed in this regard.