What we researched for this specific generation: where an enclosure actually fits, what the factory speakers are, how the factory audio is wired, and which real builds and commercial products exist for it. Confidence badges say how well each figure is sourced — this is research, not manufacturer spec.
Body styles covered: 4-Door Sedan
These are researched envelopes, not a guarantee. Measure your own vehicle — the numbers here tell you what to expect, not what you have.
| Location | trunk, through existing opening |
|---|---|
| Outer bounding box | 34"W x 16"H x 29"/36"D — the source annotates the depth as "(front to rear)", identifying the AXIS but not which of the two figures belongs to which end |
| Known obstructions | The Bose amplifier is mounted in the trunk behind a driver's-side panel — leave access to it, particularly if you are keeping the factory system. DESIGN TO 29" OF DEPTH: the pair means the space tapers, and since the source does not say which end is which, the smaller figure is the safe one (this is the catalog-wide rule established across six vehicles now carrying paired depth figures). |
| Usable volume estimate | 4 ft³ |
Suggested configurations for this vehicle, not prescriptions. Run the numbers in the Box Builder before you buy anything.
| Subwoofers | Free-air 10" in the factory rear-deck opening ONLY if you are willing to enlarge the opening and fabricate a mounting panel; otherwise a single 10" or 12" sealed box in the trunk is far less work |
|---|---|
| Box type | free-air or sealed |
| Location | rear deck or trunk |
| Subwoofers | 1x12" ported in the trunk, factory deck sub left in place |
|---|---|
| Box type | ported |
| Location | trunk |
| Subwoofers | Custom component system — the source explicitly frames the trunk as having room for one, with 34"W x 16"H x 29"D of usable envelope |
|---|---|
| Box type | custom |
| Location | trunk |
Sizes and depths below are what research turned up for this generation. Confirm against your own vehicle before cutting or ordering — trim levels vary.
| Factory speaker size | 6-3/4" woofers on BOSE cars — replaceable with same-size component woofers, or 5-1/4" or 6-1/2". NON-BOSE CARS ARE DIFFERENT AND HARDER: you must go to 5-1/4", and doing so requires CUTTING OUT THE BACK OF THE PLASTIC CUP/BRACKET that holds the stock speaker. Establish which system your car has before ordering. |
|---|---|
| Known obstructions | NO WIRING HARNESS IS AVAILABLE for this location — Posi-Products connectors to tap the factory wiring are the documented workaround. On non-Bose cars the plastic speaker cup has to be cut. The source also warns generally about the plastic on this car: everything has been in place for two decades, so work slowly. Tools: Phillips screwdriver, panel tool, small flat-blade screwdriver, socket wrench, extension, 1/4" socket. |
| Adapter bracket needed | unconfirmed for Bose cars; non-Bose cars need the factory plastic cup modified rather than a bracket added |
| Tweeter | Inside the A-pillar trim panels. PRESENT ON ALL CTS MODELS REGARDLESS OF FACTORY STEREO — Bose or base, this car has A-pillar tweeters. Reasonably easy to reach, but a mounting bracket has to be fabricated (universal backstrap, hot glue or silicone all work) and you may need to source your own hardware. |
| Factory speaker size | 5-1/4", the same on Bose and non-Bose cars, secured to the BACK of the door panel. |
|---|---|
| Known obstructions | The source notes options are somewhat limited by the available space, so check mounting depth. Because the speakers thread into the door panel itself rather than sheet metal, it specifically warns to be gentle unscrewing the old ones and screwing in the new — stripping a panel is the failure mode here. Tools: panel tool, Phillips screwdriver. |
| Adapter bracket needed | unconfirmed |
| Factory amp / premium audio | The base system is already better than most — AM/FM/CD/cassette with SEVEN speakers — and above it sat an optional BOSE system, available with or without in-dash DVD-based navigation. OnStar was also available. Both the standard GM and the Bose systems are AMPLIFIED, and the Bose amplifier is located in the trunk behind a panel on the driver's side. The dash accepts a wide range of single-DIN and double-DIN receivers with a mounting kit. WHAT YOU LOSE BY REPLACING THE RADIO: the Driver Information Center, the factory XM radio, and — the one that matters — the factory warning chimes. See known_integration_products; there is a specific part for that and a safety statement attached to it. |
|---|---|
| Adding subs without a head-unit swap | Yes, and the source actively recommends considering it on this car: keep the factory radio, replace the speakers, add a 4-channel amp and a sound processor, and you retain the Driver Information Center and the stock look while spending the receiver budget on speakers and a sub instead. |
| Head unit | No replacement needed |
34"W x 16"H x 29"/36"D for a trunk enclosure, with the source annotating the depth axis as front-to-rear. The Bose amplifier lives in the trunk behind a panel on the driver's side, so account for reaching it. Separately, this car already has a factory 10" subwoofer in the rear deck — see other_speaker_locations, because replacing it is a much bigger job than the trunk route.
Each link opens the tool with this vehicle already selected.
Measure your own vehicle. Trim levels, factory subwoofer options, and mid-generation changes all move these numbers, and a box cut to a researched figure that does not match your truck is wasted wood. Where a badge reads Unconfirmed, treat the value as a starting point for your own measurement, not as an answer.