Is the wife content with the car her husband gave her, or does she also demand her share of the inheritance, and is the car considered a legitimate gift while the husband retains the right to use it and it is not registered in her name?

A woman's right to inherit from her husband is established. Any relinquishment, waiver, or sale of the inheritance before the death of the inheritor is void, as the inheritance is not due until his death. The gifting of the car is not effective, and the evidence for this is the husband's retention of the right to use it. Furthermore, merely handing over the key is not considered a valid form of possession, which makes the car part of the estate. These matters should be presented to trustworthy scholars, and in case of dispute, the Sharia court will rule on them.