Deducting/Depreciating car on Form 4562

  1.  I share the ownership of the rental property with my dad and my aunt.  We all have active participation in the rental property and we're all under a Partnership status. My dad had purchased a new car to use for the business (~54% of the time, calculated from logged miles traveled in 2019). It is my understanding that since that car does not have mine or my aunt’s name on it that only my dad can claim the depreciation and deduction for the car.  Is my understanding correct?    
  2.  The car that my dad bought has 3 co-owners.  One is my dad, the others are his wife and his stepson.  Only my dad is involved in the rental property.  Both his wife and his stepson are not involved in the rental property.  Since this is the case and my dad isn’t the sole owner of the car, can he still deduct and depreciate the car on Form 4562? 
  3.  If yes, and we’re using actual expenses to calculate depreciation, would he be deducting 100% of the actual expenses, or would he only be allowed to deduct 33% (equivalent to him technically owning 1/3 of the car)?

Thanks in advance for the help!