1998-2004 Chrysler 300M Subwoofer Box Fitment

1998-2004 Chrysler 300M LH platform — subwoofer box fitment

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

Where a box actually fits

These are researched envelopes, not a guarantee. Measure your own vehicle — the numbers here tell you what to expect, not what you have.

Trunk Likely

Location	trunk, through existing opening
Outer bounding box	38"W x 14"H x 41"/49"D
Known obstructions	None documented beyond normal trunk furniture. DESIGN TO 41" OF DEPTH — the paired figure means the space tapers and the source does not identify which end each value describes, so the smaller is the safe one (catalog-wide rule). Even at the conservative reading this is among the largest trunk envelopes in the catalog; the 49" figure is the single deepest number recorded anywhere in it.
Usable volume estimate	5 ft³

Starting points

Suggested configurations for this vehicle, not prescriptions. Run the numbers in the Box Builder before you buy anything.

Budget

Subwoofers	Powered sub in the trunk
Box type	powered enclosure
Location	trunk

Enthusiast

Subwoofers	1x12" or 2x12" sealed
Box type	sealed
Location	trunk

Competition

Subwoofers	2x12" or 1x18" ported — at 38"W x 14"H x 41"/49"D this is one of the largest trunk envelopes in the catalog
Box type	ported
Location	trunk

Door speaker fitment

Sizes and depths below are what research turned up for this generation. Confirm against your own vehicle before cutting or ordering — trim levels vary.

Front doors Likely

Factory speaker size	6-1/2" — on Infinity cars specifically a 6-1/2" 2-OHM WOOFER. Replacements can be 5-1/4", 6-1/2", or a pair of slightly oversized 6-3/4" speakers.
Known obstructions	ONE NEW MOUNTING SCREW HOLE MUST BE DRILLED for any aftermarket speaker — the source calls this the only genuinely awkward part of an otherwise simple job. Everything else is pull the speaker, disconnect the harnesses, mount the new one to the bracket, connect the wiring adapter, and reuse the factory screws. Tools: panel tool, Torx T-20 driver.
Adapter bracket needed	Yes — a mounting bracket is used, and one new screw hole drilled
Tweeter	Front door SAIL PANELS. Present on MID-LINE and both INFINITY systems, absent on the 4-speaker base car. The tweeter attaches to the bottom of the grille, which comes off with two Phillips screws.

Rear doors Likely

Factory speaker size	PRESENT ONLY ON THE 9-SPEAKER "INFINITY 2" SYSTEM. Size not published — and the reason matters, see known_obstructions.
Known obstructions	THE SOURCE HAS NOT RESEARCHED THIS LOCATION, and says so outright: "we haven't had a chance to dig into an LH with rear door speakers, but one of our commenters tells us that the process is very similar to the front doors." That is a READER COMMENT, not Crutchfield's own measurement — a materially weaker provenance than every other figure on this page, and it is labelled that way rather than presented as researched fitment. Treat rear doors as unverified and check a live fitment tool.
Adapter bracket needed	unconfirmed

Factory audio integration

Factory amp / premium audio	FOUR DISTINCT TIERS, and which one the car has changes almost everything about the job. (1) BASE: 4 speakers, no amplifier. (2) MID-LINE: adds a 120-WATT amplifier located BEHIND AND TO THE RIGHT OF THE GLOVEBOX, plus tweeters in the front door sail panels. (3) "INFINITY 1": 7 speakers, a 240-WATT amp in the same glovebox location, and a centre channel speaker in the dash. (4) "INFINITY 2": 9 speakers, 320 WATTS, adding rear door speakers. The source notes the base system "was what it was" while the Infinity systems drew very good reviews from contemporary testers. Identify the tier before ordering anything — the amplifier, the tweeters, the centre speaker and the rear door speakers each exist only from a certain tier upward.
Adding subs without a head-unit swap	Yes, and on an Infinity car it is clearly the better path — the factory amp already crosses the signal over, so a trunk build with its own amplifier sidesteps the whole problem rather than fighting it.
Head unit	No replacement needed

Known integration products

INFINITY FRONT DOOR SPEAKERS ONLY RECEIVE BASS. The source states it plainly: "The Infinity speakers are woofers, and they only receive bass signals from the factory amp." Fit a conventional full-range 6-1/2" there and it will physically mount and play, but it will only ever be handed the low end, because the factory amplifier is doing the crossover. This is the same class of trap as the Monsoon cars on other vehicles covered here (Pontiac Grand Prix, G6 and Firebird) — a factory speaker whose size tells you nothing about what signal reaches it.
NO DOUBLE-DIN. A 4"-tall receiver will not fit this dash — single-DIN only, from what the source calls a healthy selection. This is unusual among the cars added in this batch, most of which take either size, and it is a hard constraint on the shopping list rather than an installation detail.
TWO DIFFERENT DASH KITS EXIST for these cars — one with a lower pocket and one without. Crutchfield's own MasterSheet documents the version WITHOUT the pocket, so if you buy the pocketed bracket you must follow the instructions that ship with it instead.
THE FACTORY AMPLIFIER, ON ANY TIER THAT HAS ONE, IS BEHIND AND TO THE RIGHT OF THE GLOVEBOX — 120 watts on the mid-line system, 240 on Infinity 1, 320 on Infinity 2. That location is the quickest way to confirm which system a car actually has.
MIXED FACTORY IMPEDANCES: 2-ohm front door woofers and 2-ohm rear deck 6x9s on Infinity cars, 4-ohm sail-panel tweeters, and a 2.5-ohm centre dash speaker where fitted. There is no single correct impedance for this car — fitting standard 4-ohm drivers in the 2-ohm locations is the low-impedance trap documented on other vehicles covered here and will come out quieter.
NO WIRING HARNESS ADAPTER for the sail-panel tweeters — a universal backstrap to mount them and Posi-Products connectors to wire them. A wiring adapter IS available for the front door woofers.
One new mounting screw hole has to be drilled in each front door for an aftermarket speaker.

Mounting locations

Trunk Likely

trunk, through existing opening (no metal cutting)

38"W x 14"H x 41"/49"D beneath what the source calls a sleek decklid over a rather spacious trunk. The 49" depth figure is the deepest published. For anyone using the car for family duties, the source's own alternative is a compact powered subwoofer.

Build it for this vehicle

Design a box for this vehicle — Enclosure volume, port tuning, and a cut sheet.
Check door speaker fitment — Whether a given speaker physically fits your doors.
Plan a door panel — Custom panel layout for this vehicle.

Each link opens the tool with this vehicle already selected.

Before you cut anything

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.