Can you register a car if it is in someone else name?
Yes, you can register a car if the title is in someone elses name. The title is a record of the owner - the registration is a record of the driver - and in many cases these may be different people, for example, a mom letting her son borrow a car for college, borrowing a friends car for an extended time, husband and wife, etc.
Different states require different things to do this, in my state, I borrowed a friends car for over a year and walked right in to the DMV and registered it no problem. Some states require a signed document by the title holder, or some states require the registrant and title holder to go to the DMV together. Some states will allow more than on registrant on a car registration, such as a husband and wife or two roommates sharing a car.