Used Car Lot Chart of Accounts

My family started a used car lot. I am looking for assistance with posting transactions to the correct chart of accounts for the cars we buy. Each car usually has some repair work that may need to be done to it. I started with the chart of account Car & Truck (an expense account) and created sub-accounts for each piece of inventory we have and post the expenses we accrue to the correct sub-account that details which piece of inventory the expense was for. I am not sure if this is the correct way to handle it and would like some input. I use QB Online and noticed that there are chart of accounts for cost of goods sold and then the expense accounts which I have been using. Can someone give some advice on how to handle this?