Using your Rally Innovations rear splitter is easy. First, find a flat and clean surface to work on. Make sure your vehicle is parked safely. Then, take out the splitter from the package which includes both left and right sides. Use the simple bolt - on method to attach it to the rear of your Subaru WRX or STI. It's designed specifically for your car model, so it should fit perfectly. When it comes to delivery, remember that a signature will be required. For maintenance, you don't have to do much. The powder - coated finish protects it from abrasion, but you can wash it regularly with a mild car cleaner to keep it looking great. Avoid using harsh chemicals or abrasive materials as they might damage the coating. Keep an eye on it during regular drives to ensure it can withstand normal wear and tear.