Can bankruptcy help to lower my car loan payments?

It depends on the type of bankruptcy you are filing.
In Chapter 13 bankruptcy, cramming down a car loan may reduce your balance and cut your interest rate. But for that your vehicle should be worth less than what you owe.
However, in Chapter 7 bankruptcy, your car loan will not be discharged as it's a secured debt.

Chapter 7 won't help you to lower your car payments because an auto loan is a secured debt. You have to sign a reaffirmation agreement to retain the vehicle. The reaffirmation agreement waives off the discharge of debt in a bankruptcy proceeding. You have to make monthly payments to the lender. If you fail, then the lender can repossess your car.

Why you guys always buy a car with a loan. Don't do that. Save money and buy a car with cash instead of taking out a loan. Buy a small car that you can afford. bankruptcy can damage your credit score. You may not be able to get a loan, rent with better term due to the bad score.