Body Style Determines Operable vs Fixed Glass Design
Replacing a quarter window on this vehicle depends entirely on whether you drive the folding-roof version, the two-door coupe, or the four-door sedan. The four-door sedan does not use a true body quarter glass at all; its rear side glass setup relies on a division bar separating the main roll-down door glass from a small stationary vent pane held within the door frame itself.
If you have the two-door convertible, the quarter glass is an operative, frameless piece of curved tempered safety glass that drops straight down into the rear quarter cavity via an electric motor. The two-door coupe—built on the Mitsubishi-derived ST-22 architecture rather than the JR/JX platform used for the convertible and sedan—uses a completely rigid, encapsulated glass window permanently set into the C-pillar quarter frame.
| Vehicle Variant | Glass Functionality | Border & Weatherstrip Interface |
|---|---|---|
| Convertible (JR / JX) | Power roll-down (movable) | Frameless; seals against soft-top rail and front door drop-glass |
| Coupe (ST-22) | Fixed stationary | Factory-encapsulated rubber perimeter edge |
| Sedan (JR) | Fixed door vent | Housed in rear door frame behind vertical division bar |
Mechanical Regulators and Interior Disassembly on Convertibles
Because the convertible quarter window drops out of sight, accessing it involves substantial interior teardown before I can reach the three primary regulator bracket bolts. I have to unclamp or partially retract the soft top, lift out the lower rear bench cushion, take out the rear seatback, and pull the interior quarter trim along with the rear speaker grilles. The glass attaches directly to an internal scissor and cable-driven power regulator track tucked inside that steel inner quarter cavity.
These convertible regulators endure significant stress. The drive cables snap, the small plastic pulleys fracture, and the grease inside the drop channels hardens from infrequent use, which leaves the green-tinted Solar Controlled pane stuck midway. If the window jams while the soft top is being operated, the folding roof frame brackets can strike and shatter the tempered glass. Whenever I supply replacement units for these cars, I use quality aftermarket glass sourced from manufacturers like Pilkington, PGW, FYG, or XYG to match the original factory curve and solar green tint without using dealer stock.
Frameless Glass Alignment and Water Ingress Points
Unlike the coupe, which relies on a fixed perimeter rubber molding, the convertible quarter glass has no metal frame along its upper or forward perimeter. It depends strictly on accurate mechanical indexing to prevent wind buffeting and cabin water leaks. The forward leading edge presses directly against the vertical weatherstrip on the back of the front door drop-glass, while the top contoured edge seats into the folding roof weatherstrip channel.
The internal regulator carriage features mechanical eccentric fasteners and slotted adjustment bolts to control three distinct axes:
- Vertical height: Ensures the upper rim beds firmly into the folding top rubber without binding against the roof structure when the door closes.
- Inboard and outboard pitch: Sets the inward tilt of the glass so the frameless top edge maintains constant pressure against the side roof rail seals.
- Fore-aft parallel positioning: Closes the vertical seam against the front door drop-glass rubber to eliminate whistling at highway speeds and stop rain from leaking through the door joint.
Neither the coupe nor the convertible quarter glass contains integrated defroster wiring, diversity radio antennas, or bracketry for forward-facing safety cameras; rear defogging is handled strictly by the separate glass window in the rear fabric or backlite panel.
