You can no longer do a 1031 exchange for vehicles ... so you will take the first out of service and enter the new one from scratch.

assuming it was used in your self-employed business it would be enter on schedule C using the auto entry questions. the old vehicle would be deemed sold for the insurance proceeds (the proceeds would need to be prorated between business and personal % of use)

So do I only report the proportionate percentage of the insurance payout equal to the Business use portion of the vehicle use?

EG: So, if say I received $20,000 proceeds and the car was used 70 % for business, do I only report $14,000 as proceeds?

You will enter the full amount, the program will apply the business percentage. You will need to verify depreciation taken. If you used actual, add the numbers. If you used standard, multiply the miles each year by the depreciation portion.

The annual depreciation amount per year included in the Standard Mileage  per IRS Publication 463 (Page 23) Car Expenses

• 2012 - $0.23
• 2013 - $0.23
• 2014 - $0.24
• 2015 - $0.22
• 2016 - $0.24
• 2017 - $0.25
• 2018 - $0.25
• 2019 - $0.26
• 2020 - $0.27
• 2021 - $0.26
• 2022 - $0.26

Be sure to thoroughly review your return before filing for accuracy.

To see your forms:

• In desktop, switch to Forms Mode. 
• For online, see How do I preview my TurboTax Online return before filing?