Your BMW 635csi has a fin-like structure at its rear that appears, at first glance, to add a stylish accent to your ride. That's what's known as its rear spoiler. It has a second important purpose, too: to cut down on air resistance during driving, making your luxury sedan even more aerodynamic. The result is a smoother, more comfortable ride. How does a BMW 635csi rear spoiler work, exactly? It forces air to move across your car's body in a way that minimizes drag. Keeping that resistance low can improve both traction and fuel efficiency. Many rear spoilers for BMW 635csi sedans are made of high-quality materials like ABS plastic or fiberglass, while others are made of silicone or even carbon fiber. Though they're built durable, road hazards and bad weather can nonetheless wear on any spoiler. That's not to mention that even minor debris and collisions can damage them. Luckily, we've got the best BMW 635csi rear spoilers you can get for replacement in stock, straight from the factory, right here at our auto parts counter. You can even order online and have your new spoiler shipped directly to you in no time. Buy now and save time and hassle!