If a seller won't let you get the car inspected, it's probably a good idea to walk away and look for a different seller. It's possible that they are trying to hide something problematic that an inspection might reveal. Unless the car you’re considering is one-of-a-kind or vintage, you'll likely find plenty of other options for buying a used car. Spending $100 or so on a mechanical inspection can save you the hassle of potentially thousands of dollars in repairs down the road.