create the fixed asset structure in the chart of account you want  to use, then create the associated liability accounts, all with zero starting balance

get the current loan balance, journal entry, debit fixed asset and credit the loan liability

the difference between the book vale per fixed asset in the old file, and the new balance you just created now can be entered, another journal entry, debit fixed asset, credit owner equity for that difference

Don't overlook Depreciation.

Fixed Asset Vehicles

Subaccount Cost Basis

Subaccount Deprec

Debit Cost Basis for basis

Credit Deprec for prior Deprec

Credit Loan balance as of this same transition date

The difference is Credit/Debit to Retained Earnings (prior year equity)

teach - I didn't overlook depreciation, I said to use prior book value, which is cost less accumulated deprecation

can you send me a screenshot 

"I said to use prior book value"

That's Net. Since this is the same business, just starting the data fresh, you need Gross. You need original Basis and you need all taken depreciation.

"can you send me a screenshot"

I attached an example of a chart of accounts structure that works fine. You can track per vehicle, as you show. You can have a total of 5 levels.