The account length in the ledger should be 5 or 6 digits (with sub-accounts). If it's not, change the account length in the client details form, Ledger tab, then select Tools, Repair accounts, and Fix account length in the ledger.
Manually create header accounts for each vehicle, 75001, 75002, etc. (or 75001, 75002, etc. for 5-digit long account). It's a header account and it should keep the name 'motor vehicle.'
Create transactions to motor vehicle accounts. Use the master codes and sub-accounts to represent motor vehicle (if account 750001 is Car1, then 751001 account will be Fuel and motor oil for Car1).
Print the financial report. When the motor-vehicle header account exists, the Notes to Financial Statements will print all sub-accounts with balances for the motor vehicles: lease note, the above will print only if you allow sub-accounts in the financial report options.