BMW Z3 Model 68 Subwoofer Installation Instructions

Read these instructions from start to finish twice before you even go near the car! Professional installation is recommended for those who are unfamiliar with car audio. These instructions assume you have already installed your new amplifier.

Remove old enclosure:
1. Carefully remove the subwoofer enclosure cover by first lifting the rear edge of the cover and then lifting entire cover straight up. The cover should lift out with minimal effort, but may require some additional effort to release the rear snaps. Take your time and be careful when removing the sub lid! The easiest thing to do is to insert a flat, metal, handled-tool like a stiff putty knife and carefully pry each side up from the back. NOTE: If you have the storage compartment, you may find it easier to temporarily remove the storage compartment lid while performing the install.
2. Remove the 4 mounting screws (2) from the existing speaker enclosure (1). If you have the storage compartment, remove the screws holding the compartment liner and lift out the liner.
3. Remove the old enclosure (1) by pulling upwards. Disconnect the wiring harness connector (2) and remove the entire enclosure from vehicle.
4. Using a knife, diagonal flush cutters or small saw, carefully trim away the 4 plastic extrusions (2). If you have the storage compartment, remove the (4) center extrusions—Do Not re- move the extrusions the storage compartment lid hinges mount to.
5. Remove the old foam insulation from the rear panel of the sub compartment. Remove the backing from the sound matting and apply in the upper center portion of the rear plastic panel. Press matting firmly against panel to ensure complete adhesion.

Prepare the Subwoofer Compartment
Overview: The Model 68 enclosure is designed with the speaker facing toward to the rear of the vehicle. The “L” shape in the back/bottom of the enclosure faces the front of the vehicle, and rests over the beam that runs sideways through the enclosure compartment. The protrusions on the speaker side of the enclosure are standoffs to ensure proper clearance between the speaker and the plastic panel at the rear of the subwoofer compartment. The round hole drilled from top to bottom in the back of the enclosure (the part towards the front of the vehicle) accommodates the mounting bolt. The wire terminal cup mounts in the rectangular hole in the driver’s side of the enclosure.
1. The Cut (2) 12” and (2) 3” lengths of the Black Foam Gasket Tape. Remove the kraft pa- per backing and attach one 12” length to each downward facing horizontal section of the enclosure. Be sure not to cover the hole for the mounting bolt—place that length of gasket between the mounting hole and outside edge of the enclosure. Attach the two 3” lengths to the front of the standoffs on the speaker-side of the enclosure.
2. Place the enclosure in the subwoofer compartment. Push the enclosure down and toward the front of the vehicle—you want to make sure the “L” shaped notch in the enclosure is as close to flush against both sides of the beam as possible. Make sure the enclosure is centered side-to-side as well. While holding the enclosure in place, use the center punch or marking pencil to mark the center of the mounting bolt hole on the top of the beam. The accuracy of this mark is critical, so take your time and be certain you’ve got it marked correctly—double, triple, quadruple check it!!
3. Remove the enclosure and drill a 7/16” hole in the location marked in step 2. A good quality Cobalt metal drilling bit will make this step easier. The beam is hollow, just drill a hole through the top and stop.
4. Insert the Rivet Nut into the hole drilled in step 3. Insert the 1/4” x 1” hex bolt through the Rivet Nut Installation Wrench and thread the hex bolt into the Rivet Nut. You want the Rivet Nut Installation Wrench oriented with the “grip dots” facing the Rivet Nut. Use a 7/16’ wrench or socket to tighten the hex bolt until the Rivet Nut is securely fastened in the hole. (NOTE: The picture at right shows a thumbscrew threaded into the Rivet Nut rather than the hex bolt included with your kit). Remove the hex bolt and installation wrench. The Rivet Nut should remain secure in the hole.

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