How do I report a new Car (plug-in hybrid) that I bought in December and used 100%in my Business?

It depends. If you report your income on a Schedule C (if you are a property manager), you can enter it as one amount. If the rentals are reported on Schedule E, report the vehicle expense separately on each corresponding property.  

You will choose whether to take the actual vehicle expenses or use the standard mileage rate to figure your vehicle expenses. If you claim the standard mileage rate in year one for this vehicle, you will have the option of deducting the standard rate or actual expenses in subsequent years. 

If you claim actual vehicle expenses in year one, you must choose actual expenses in every subsequent year for that auto.