Rattle

On my 2017 R, I noticed a rattle that only happened when I was around 3-4K rpms. Sounded like a heat shield and only happened when the car was warm. Took 2 trips to the dealer for them to finally be able to reproduce it but it turned out to be one of the valves in the muffler. Figured I would post about this so that if someone has a similar issue in the future, a search will pull up this thread. Car has 1500 miles

It only happens once your car warmed up? Or when it was cold? I have a rattle at 3-4k rpms I'm hearing but it's usually only when it's still cold. My dealer says it's the Piston slap but I'm almost inclined to believe it's the valves since I can only hear it in sport mode with the valves open. Any chance it sounds like:

https://soundcloud.com/user-863107763/voice-006-sd

Correct, I only heard the rattle when warm. From the sounds you shared, mine was louder and also it was audible in all exhaust modes.