The vehicle should have been carried as a fixed asset, something like this
fixed assets:
car model
>> car cost
>> accum. depreciation car
1. calculate and post partial year depreciation on the car
2. create create a new car fixed asset car structure like the above
3. journal entries
debit accum. depreciation car for the balance in the account, credit new car cost account
debit new car cost account, credit car cost fixed asset account for the balance in the account
then
debit old loan 10K
debit new car cost 12K
credit new loan 22K