How to record 179 expensing?

Hi folks,

Our business just bought a Mercedes on 01/16/2016 for 45K and we only expensed $11,060 under section 179.

I only booked a JE so far to reflect the purchase: Debit Vehicle account and Credit Cash account.

For monthly depreciation, do I calculate it based on the full cost 45K of the vehicle or only $33,940?

How do I record the 179 expense in this case?

Thank you!

Nhi