Only the older Model 3s have the vent opening in the rear parcel shelf because Tesla covered that up sometime in 2019, IIRC. My early 2018 Model 3 has it and I drove around with the port covered for a few years with a piece of foam wrapped in acoustic cloth. Not sure if I noticed much difference because I'm usually listening to music or podcasts. Since Tesla recently added the ability to stream music from Tidal and I wanted maximum effect from the subwoofer, I removed the foam covering the vent. I haven't really noticed an increase in noise, but like I said I'm usually listening to something in the car AND I have a little hearing loss. If you think it will work it's worth a try, especially since the front door speakers have plenty of bass to make up for any small reduction from the trunk subwoofer.