Now is when you create an asset for the vehiclemail in your chart of accounts. If you are borrowing any of the buyout you will also create a loan liability account. You can use the expense screen or check writing screen if you did write a check and will post the purchase price and any loan in the one transaction.

Example buyout of $1000 (including tax, title,etc) with $2000 cash due your expense from banking would be

Asset account $10000
Loan account  ($8000)
Net check.   $2000