I typically put the Purchases (cost basis) as Fixed Asset, so that it is Found later, even if the amount is totally taken as Accelerated Depreciation Expense. That way, you have the Clarity.

Vehicle Parent Level Fixed Asset
Subaccounts: Cost and Depreciation

The Purchase is Cost = Debit the Cost Fixed Asset Account
The Depreciation taken as expense = Credit to the Fixed Asset account

Never post to the Parent Level; it will be the Net of both.

Equity is not involved here.