The most common cause of car repossession is when a borrower stops paying their loan or breaks the terms of the contract in another way, like not having the right auto insurance. But it can happen for a whole host of reasons, and there are state laws in place to ensure lenders get their money.
The first thing to remember is that repo men are a lot like Liam Neeson. They will find your car if you try to hide it, and they'll keep coming until the vehicle is either removed or destroyed in a legal auction. If you fight the repossession process in any way, you could end up being injured or arrested, plus your lender will pass on the costs of those attempts to you. You also can't "breach the peace" by threatening or physically stopping a repo company from taking your car.
When a vehicle is repossessed, it's usually prepped for a public sale to cover the remaining auto loan balance. The lender is required to advertise the car fairly and conduct the sale at a time and location that is commercially reasonable. In the past, this might have meant holding an auction at a local garage or in a nearby parking lot. But these days, repo agents can use advanced towing equipment that makes it easier than ever for them to extract vehicles from tight spots. That means they might have to survey your driveway before you head to Wal-Mart or your workplace, and it's possible your car could be repossessed as you leave for the grocery store or a restaurant.