2015 legacy 2.5i premium (eyesight, no moonroof): over the past 2 months I have noticed that after a cold start in the morning or getting off from work, when I accelerate my car makes a rattling/metal noise. It lasts about 20 minutes then goes away. noise is mostly coming from the driver's side, could be dash or engine. No improvement as I push down on the dash. It has been getting louder over the past 2 months. it happens around 1200-1400 rpm then goes away if i accelerate even more. I have to keep it at that RPM and can keep it going for more than 10 seconds. The dealership kept the car for 2 days trying to figure out what was wrong. Actually many mechanics tried to figure out what was wrong. They called up Subaru of america and they didn't know. They checked the heat shields and everything else. I sent SoA the video and told them to blast up the sound to hear it better. A technical case was started and SoA will notify the dealer if anything comes up. Take a listen. Heard at 0:03 and 0:10-0:12 (best heard) 0:14 0:19-0:21 0:32

https://www.youtube.com/watch?v=4kZxZjhS4c0