Yes, you can take two different types of depreciation for two different business vehicles. You must use the property more than 50% for business to claim any section 179 deduction
What are you going to do with your old car? Retire it to personal use? Continue to use both for work? Sell it? At the point in time when you sell, you must recapture the depreciation taken. Even though you used standard miles, you must use the mileage recapure rate found in Pub 463.
https://www.irs.gov/pub/irs-pdf/p463.pdf
