Buying a car during a Chapter 13 case is more complex because you are in a 3- to 5-year court-supervised repayment plan. How Soon After Chapter 7 Can I Buy A Car? - Ascent Law

: You do not legally have to wait for the final discharge (usually about 90 days after the 341 meeting) to buy a car. However, some traditional lenders may prefer to see the official discharge papers before approving a loan.

: You do not need the court's or the trustee's permission to buy a car in Chapter 7. Chapter 13: Reorganization Bankruptcy

In Chapter 7, you are generally free to acquire new debt or property once your case is filed, as post-petition earnings are not part of the bankruptcy estate.