As of my knowledge cutoff date in September 2021, the highest option package available for the 2018 Subaru Outback was the Touring trim level. The Subaru Outback Touring trim typically includes a wide range of premium features and upgrades, making it the most well-equipped and luxurious option for the 2018 Outback model year. Some of the features commonly found in the Subaru Outback Touring trim (note that features may vary by model year and market) include: 1. **Leather Upholstery:** High-quality leather seats and leather-wrapped steering wheel. 2. **Upgraded Infotainment System:** A larger touchscreen display, often with features like navigation, smartphone integration (Apple CarPlay and Android Auto), and premium audio. 3. **Power Moonroof:** A panoramic or power-sliding moonroof for an open and airy cabin experience. 4. **Harman Kardon Audio System:** An upgraded audio system from Harman Kardon, known for its superior sound quality. 5. **Woodgrain Interior Accents:** Woodgrain trim or other premium interior accents to enhance the cabin’s aesthetics. 6. **Safety Features:** Additional advanced safety features, such as blind-spot monitoring, rear cross-traffic alert, and sometimes even Subaru’s EyeSight Driver Assist Technology. 7. **Exterior Upgrades:** Stylish exterior touches like chrome accents and unique alloy wheel designs. Please note that specific features and packages can vary depending on the market and region. Subaru may have introduced new options and packages for the 2018 Outback, so I recommend checking with a Subaru dealership or the official Subaru website for the most up-to-date information on available trims and packages for the 2018 Subaru Outback in your area.