There is the main liner with the rear part & a front liner piece. Put the part #s into realoem.com & you'll see where they go. Or better, put your VIN in at the start page & you'll be directed to the parts used on your car.
https://www.realoem.com/bmw/enUS/select
Then go to vehicle trim, then to insulation.
https://www.realoem.com/bmw/enUS/sho...78#51717039677
https://www.realoem.com/bmw/enUS/sho...78#51718265467
2006 330ci ZHP - Silbergrau Metallic / Stoff Laser/Anthrazit / Alu Black Cube trim / Adaptive Xenon headlights / HK hi-fi system / heated front seats