Designed and tested noise generator delete plugs on R56 Mini Cooper S. Should work on similar models (R55, R57, R5x). Two parts:

• stl files generated from Tinkercad.com
• 3mf files generated from Bambu Studio

I used a Bambu A1 Mini; 0.4 mm nozzle, standard flow and print process (0.2mm layer height). I chose 3 wall loops and 5 layers top and bottom shell, 1mm thickness. Supports are needed for the Firewall Plug regardless; though substantial supports were used for the 3mf provided as described below.

Hose plug: I've seen silicone hoses, plastic replacements for the OEM connector with noise maker take-off, and hose plugs. I chose the hose plug, modifying a design by coltonhosley - https://www.thingiverse.com/thing:3904395 - to better fit my rubber hose. You'll need to cut the rubber hose about 2 inches long and reuse the hose clamps.

Firewall plug: I've not found a solution to plug the firewall hole. After several design iterations I settled on a version that fits tightly. I used some closed-cell foam about 20mm tall (yes, above the top of the finished print) cut to fit within the cavity. There's a plastic 'top' where the firewall pipe curves inward to the cabin which will prevent the foam from getting lost in the plumbing. The plastic tabs were the trickiest part of the design. I ended up cantilevering them from above and leaving a gap on the bottom to squeeze with my nails or a screwdriver for removal (see reflection in Noise_Delete_Firewall_Plug_Installed.jpg). Printing the file on its 'bottom' face resulted in tabs snapping, so I laid the part on it's side where the filament will print along the length of the tabs. Extra support material required for printing this orientation is worth the cost for reliable retainer tabs.

Cheers, and enjoy a quieter ride with less engine bay clutter! Nike Zeus