Rattle on B7

Hey guys! 2015 TDI. Need help identifying or tips on finding a rattle. I have a rattle coming from the middle of the dash but goes away under engine load but comes back while idling. Used a stethoscope I promise it’s not the DMF. A rattle coming from the lower heater core mound on the firewall, can also hear it just above the gas pedal. Any tips are appreciated!