Left Rear Door Seal Retainer / Seal Guide Channel – 4K8839151

Original mounting rail / support profile for the left rear door seal (internal guide and stabilizing strip for the door aperture seal / frameless window trim on the driver's side), designed for Audi A7 Sportback, S7 and RS7 (4K / 4K8 generation) models produced from 2018 to 2026, including versions with 3.0 V6 TFSI (55 TFSI), 2.0 TFSI (40/45 TFSI), TDI diesel engines, and 2.9 TFSI (S7) and 4.0 V8 TFSI (RS7) sport variants, based on the modular MLBevo longitudinal platform.

Original VAG group bodywork mounting and structural component. Made of profiled, lightweight technical alloy / hardened plastic with a precisely selected cross-section, resistant to thermal deformation, moisture, and repeated dynamic loads. Mounted directly on the edge of the left rear door frame. Ensures secure, gap-free retention of the seal along the entire door edge, guarantees a perfect fit against the bodywork and frameless side window, prevents the rubber from slipping during opening/closing, and prevents air whistling and moisture ingress into the cabin at highway speeds.

Technical specifications:

• Catalogue part number (OE): 4K8839151 / 4K8 839 151 (interchangeable with revisions 4K8839151A, 4K8839151B, 4K8839151C; the right-hand side component is available under number 4K8839152)

• System / Category: Bodywork components / Doors, mounting profiles and seals (Rear Door Weatherstrip Retainer / Seal Guide Channel Left)

• Function: Mounting strip / guide rail for the left rear door seal

• Color / Material: Black (technical plastic / OEM profiled support plastic)

• Body side: Rear – left door (driver's side)

• Dedicated model: Audi A7 Sportback / S7 / RS7 (body type 4K8)

• Steering side: Left (LHD) and Right (RHD) – symmetrical component for the left rear door

• Design: Precisely profiled rail with an integrated guide channel for the seal mounting lip and factory mounting points

• Condition: Original part, used (100% functional – profile is straight, without bends or cracks, guide channel is undamaged, all mounting clips are intact)

• Manufacturer: Audi AG / VAG (OEM Original)

Main application:

• Audi:

  • A7 Sportback (type 4K8) – model years 2018 to 2026 (all engine and equipment versions)

  • S7 Sportback (type 4K8) – model years 2019 to 2026

  • RS7 Sportback (type 4K8) – model years 2019 to 2026

Fitment guarantee and VIN verification

Every mounting component undergoes a detailed profile straightness check and inspection of the mounting holes before shipping.

Fitment / installation tip: The initial designation 4K8 (body group 839 – rear doors) confirms the geometry is adapted to the specific frameless door profile in the Sportback body. The proper condition of this support strip is crucial in cars with frameless window doors – any crack or deformation of the profile causes the seal to pull away, leading to annoying wind whistling at higher speeds or water leakage during pressure washing. Before purchase, we recommend comparing the OE part number embossed on the part or verifying the fitment using the vehicle's VIN.