It might be tempting to skip the part of a car purchase that involves talking to salespeople at the dealership, but it's just not a practical or financially sound decision because you can actually negotiate the price down based on what you learn. When you test drive a car, you can determine whether it's a smooth and comfortable ride. If you have a long commute, you don't want to spend a month's pay on a car only to find out that the driver's seat is extremely uncomfortable, your head hits the roof, and the windows don't block out any traffic sounds.
Even beyond these basics, which may not feel important to every driver, it's important to make sure every component of the car works correctly. Test driving a vehicle gives you the opportunity to check out the headlights, windshield wipers, radio, seat warmers, and any other feature that might be prone to malfunction. Once you've checked all of these things, the knowledge you gain will give you the upper hand when it comes to negotiating with salespeople.