If the accident is covered under the provisions of a cognizable offence, such as Section 279 of IPC and/or section 337 or 338 of IPC (as it happens in such accident cases), then it is mandatory to register the FIR as per Lalita Kumari judgment of the Supreme Court [see this topic: http://tilakmarg.com/forum/topic/whether-lalita-kumari-case-is-final-or-any-further-judgment-case-later/%5D.
If the police station is refusing to register the FIR, you can approach the DCP of the area concerned. If required, you can also file a private complaint case in the court.
If you have given the car to the police station on a written seizure memorandum, then the police would be responsible for the loss of vehicle.
Dr. Ashok Dhamija is a New Delhi based Supreme Court Advocate and author of law books. Read more about him by clicking here. List of his Forum Replies. List of his other articles. List of his Quora Answers. List of his YouTube Videos.