In QuickBooks Online, there are ways to record your second-hand car purchased by your company.
One way is to record it by creating a check. Here's how:
Go to the +New button.
Enter the necessary information.
Choose the correct Bank/Credit Account.
Under the Category drop-down, choose the asset account, and enter the Amount.
Click on Save and Close.
If you haven't categorized the vehicle into an Asset account, you can follow the steps below. Before proceeding, I'd highly recommend consulting with your accountant to make sure that this is recorded properly to avoid errors in the future. They can also share other ways to input this into the system.
Go to the Accounting menu.
Within the Chart of Accounts tab, select New.
Under Account type, select the appropriate type of account.