High roof wing with side flaps for Mercedes G-class W463A Gronos

High Roof Wing with Side Flaps — Track-Aesthetic Spoiler for Mercedes G-Class W463A Gronos

The Mansory High Roof Wing with Side Flaps is the most overtly motorsport-derived of the rear-roof spoiler family. The base wing carries the same elevated profile as the standard High Roof Wing — 145 mm trailing-edge extension, 9° attack angle, +75 mm above OEM roof — but adds vertical end-fence flaps at each tip, projecting downward from the main wing element. The result is a defined three-element aerofoil reading at the rear-roof position: main wing with flow attached across its span, organised wake with fence-controlled tip vortex behaviour.

What Side Flaps Do — The Aerodynamic Case

End-fence flaps are a textbook racing-wing technique. They serve three coupled purposes:

• Tip vortex reduction: a free-tipped wing element generates strong tip vortices as high-pressure air below the wing migrates upward to the low-pressure region above the wing tips. End fences block this migration, reducing tip-vortex strength and the associated induced drag.
• Effective span increase: by reducing tip-flow leakage, the wing's effective aerodynamic span is increased — closer to its physical span. This means more of the wing's area generates useful downforce.
• Wake column organisation: the side flaps shape the rearward wake into a more defined column rather than allowing it to expand laterally. The rear of the vehicle moves through the air with a cleaner wake signature, with measurable benefits in cross-wind stability and trailer-yaw behaviour.

Quantified Performance

• Downforce at 200 km/h: 32-38 kgf at the rear axle (vs. 22-28 kgf for the High Wing without flaps, vs. 8-15 kgf for the standard wing).
• Cd impact: 0.011 increase vs. OEM (small, similar to High Wing alone — flaps add lateral surface but reduce induced drag, partially offsetting frontal-area increase).
• Cross-wind stability: measurable improvement in steering correction frequency under 60 km/h cross-wind gusts during sustained 180 km/h cruise.
• Trailer-towing yaw stability: reduced yaw oscillation when towing trailers above 1500 kg at sustained motorway speed.

Side Flap Geometry

• Flap dimensions: 220 mm tall × 95 mm chord at base, tapering to 60 mm chord at top.
• Flap angle: 8° outward toe at the base, 4° at the top — wedge-shaped to follow the wake column geometry.
• Flap profile: aerofoil cross-section, 12 mm maximum thickness, sharp trailing edge.
• Mounting to main wing: permanent integration during layup — the flaps are not bolted accessories, they are co-cured with the main wing element.

Visual Presence at the Limit

The side flaps push the build personality firmly into the racing-aesthetic register. From the rear three-quarter view, the rear of the vehicle reads as engineered, instrumented, performance-purposed — closer to a homologation special than a luxury SUV. This is a deliberate choice; the High Roof Wing with Side Flaps is for buyers who want their G-Class to declare its modified status without ambiguity.

• Side profile: the elevated wing plus vertical flaps create a dramatic "stepped" upper-rear silhouette — instantly recognisable as a race-derived aero element.
• Rear-three-quarter: the flaps add lateral mass that anchors the wing visually against the rear-quarter glass, creating a strong geometric frame.
• Photography: golden-hour and contre-jour shots benefit from the flaps catching light differently from the main wing, adding compositional interest.

Construction

• Material: autoclave-cured carbon, 2x2 twill 200 g/m² visible weave; sandwich core with aluminium internal frame.
• Mass: 3.0-3.4 kg complete assembly.
• Frame: aluminium spar through main wing and into flap roots, ensuring the flaps remain rigid under aerodynamic loading.
• Cure: autoclave 130°C / 6 bar / 6 hours, post-cure 80°C / 4 hours.
• Finish: UV-stable two-pack clear coat in gloss or matte; painted-composite version available on lead-time.

Installation

The High Roof Wing with Side Flaps installs to the same OEM roof anchor points as the standard High Wing, with one additional consideration: the side flaps require careful clearance verification with the OEM roof rails and rear-quarter glass. Hodoor supplies a fitment template that confirms clearances on the buyer's specific chassis variant before bonding.

• Pre-fit verification: 8-10 mm minimum clearance between flap inner surface and rear-quarter glass.
• Adhesive: Sika 252 polyurethane structural adhesive at perimeter contact zones.
• Mechanical fasteners: 6 anchor points along OEM roof rear edge.
• Cure: 24 hours before driving.
• Total install time: 5-7 hours.

Pairings

• With Wide Kit body, aggressive front (Bonnet II + performance grille + carbon fenders): the most cohesively aggressive build configuration — a complete track-aesthetic Gronos.
• With Bonnet IV (race-spec): upper-bodywork airflow philosophy from front vortex strakes through to rear wake-organising flaps.
• Stealth/matte builds: matte clear-coat carbon flaps and wing read as deep dark surfaces; appropriate for builds where the racing geometry is the statement, not the carbon visibility.

FAQ — Side-Flap Variant

Q: Are the side flaps detachable from the main wing?
A: No. The flaps are co-cured with the main wing during autoclave processing — they are a single bonded structure. Buyers who want flap-removable functionality should consider the standard High Roof Wing instead.

Q: Can the flaps catch on garage door frames or low overhangs?
A: The flaps project downward from the wing trailing edge, not sideways or rearward. They sit within the vehicle's overall footprint when viewed from above. Standard garage doorways and parking structures present no clearance issue beyond the basic vehicle-height check (2.04 m total).

Q: Is this configuration street-legal in EU/UK markets?
A: Yes, when fitted as a bonded/bolted aerodynamic component with rounded edges and no pedestrian-injury hazards. Mansory's certificate of conformity is supplied for TÜV/MOT use. Some markets may require independent type-approval verification.

Order the High Roof Wing with Side Flaps

WhatsApp +44 7488 818 747 — specification, finish, fitment by VIN
[email protected] — quote, lead-time, freight

Parent Mansory G-Class Gronos kit · Mansory G-Class catalogue.