Spoiler vs wing comes down to where the air goes. A spoiler sits on the body, usually the trunk edge, and blocks or redirects the air flowing over it. That cuts lift at the rear. A wing stands up on supports with air flowing over and under it. It works like an upside-down aircraft wing and pushes the car down, at the cost of extra drag.
At legal street speeds, both do far less than they do on a track, and the BMW, Porsche and NASA sources below explain why. After that we go through the styles we sell for the M3, M4 and M2.
Key takeaways
- A spoiler sits on the body and “spoils” airflow to reduce lift. A wing is an airfoil on stands that makes downforce.
- Wings add drag. Spoilers on road cars are often meant to cut it.
- Aero force grows with the square of speed, so at 35 mph you get about a quarter of the force you’d get at 70 mph.
- Our spoilers and wings are styling parts. We don’t publish downforce figures for them.
- Lip spoilers and ducktails usually mount with tape or screws. A wing mounts on stands, and a CSL-style trunk replaces the whole trunk lid.
What is a spoiler on a car?
A car spoiler is a device designed to “spoil” unfavorable air movement over a moving car. That air movement usually shows up as lift, turbulence or drag. The name comes from aircraft, where a spoiler is a panel that reduces a wing’s lift on purpose.
The classic example is Porsche’s ducktail. According to Porsche’s own history of the 911 Carrera RS 2.7, the wind tunnel showed a rear lift coefficient of 0.29. The ducktail cut that by two-thirds, to 0.08. It also improved drag and raised top speed by 2.8 mph, to 149 mph, so the little lip made the car quicker in a straight line as well.
What is a rear wing?
A wing is an airfoil, the same basic shape as an aircraft wing, mounted upside down. Air passes both above and below it, and the shape and angle turn that flow into downforce. Downforce adds vertical force on the tires, which means more grip.
You pay for that grip in drag. A wing adds it, while many road-car spoilers are shaped to reduce it. Because air has to pass underneath, a wing sits up on stands with a gap between the blade and the trunk.
The conventional mount holds the wing from underneath, but race cars moved to “swan neck” mounts that hold it from above. In a Racecar Engineering article on the swan neck, Michael J. Fuller explains why: at aggressive angles, a mount under the wing became a source of flow separation, and top mounts cleared it.
BMW uses the same idea. Its M Performance Track Kit for the M2 includes a manually adjustable swan neck rear wing, as used on the M4 GT4 and M4 GT3 race cars. It has two angle settings and a “Race Mode” that moves the wing 50 mm rearward. BMW lists the kit as road-legal and built for track days.
Rear wing vs spoiler: side by side
| Spoiler | Wing | |
|---|---|---|
| Where it sits | On the body, usually the trunk edge or roof | On stands, above the body |
| Airflow | Over the top only | Over and under the blade |
| What it does | Cuts lift and turbulence | Makes downforce |
| Drag | Often meant to reduce it | Adds drag |
| Typical mounting | Tape or screws on the trunk lid | Stands on the trunk lid |
| Look | Subtle, follows the body lines | Race car |
Types of spoilers and wings
Lip spoiler
A small lip along the trailing edge of the trunk. Our OEM++ spoiler for the G87 M2 is one. The listing describes it as a short lip that sharpens the trunk’s edge and sits low, so it keeps your view out of the rear window clear.
Ducktail and high kick
A ducktail rises from the trunk lid and ends in a flat, upturned edge, like the Porsche original. We use “high kick” for a ducktail with a taller, steeper trailing edge. Our best-selling spoiler for the G80 M3 is a high kick ducktail.
Integrated trunk (CS and CSL)
Here the spoiler is molded into a carbon trunk lid. BMW’s M4 CSL press release says its carbon trunk lid weighs 6.8 kg (about 15 lb) less than the M4 Competition’s and has a prominent integral spoiler, echoing the 2003 M3 CSL. BMW says that spoiler “generates significant rear-axle downforce in dynamic driving situations.” The M2 CS spec sheet lists a “CFRP trunk with integrated Ducktail.”
Roof spoiler
On an SUV like the X3M, the spoiler sits at the top of the tailgate, above the rear window. See our X3M and X4M spoilers for this type.
GT wing
This is a full wing on stands, often with end plates. Our MP-style and AD-style wings for the G80, G82 and G87 are in this group. The AD-style listing describes swan-neck, high-mount geometry and includes the stands and mounting hardware.
Rear spoiler aerodynamics at street speeds
NASA’s lift equation shows that the force on an airfoil grows with the square of velocity. Downforce is lift pointed at the road, so the same rule applies. Double the speed and you get four times the force. Halve it and you get a quarter.
So a part that works at track speeds makes far less force on the way to work. Back in 1969, Car Life magazine tested AMC’s roof spoiler on the Javelin. It found no reduction in lift below 115 mph. Some carmakers say plainly that their spoilers are for looks only.
That’s our position too. We sell our spoilers and wings as styling parts, and we don’t publish downforce figures for them. The OEM++ listing says it directly: it changes how the rear looks, and we make no claims about downforce. If you track an M2 and want tested aero, BMW developed the Track Kit above in its own wind tunnel for that job.
What does change on the street is the look and your rear view. A lip spoiler keeps the rear window clear. A tall wing sits in it.
Our spoilers and wings for the M3, M4 and M2
Prices are at the time of writing (October 2026). Prices change, so check the product page.
| Car | Part | Type | Price | Mounting (per listing) |
|---|---|---|---|---|
| G80 M3, G20 3 Series LCI | High kick ducktail | Ducktail | $399 | 3M double-sided tape, no drilling |
| G80 M3 | CS-style spoiler | Trunk lip | $425 | Not stated, ask us |
| G82 M4 | Ducktail spoiler | Ducktail | $399 | Predrilled holes, self-tapping screws included |
| G87 M2, G42 2 Series | OEM++ spoiler | Lip | $449 | Ask us |
| G87 M2, G42 2 Series | MP-style spoiler | Spoiler | $399 | No drilling |
| G80, G82, G87 | MP-style wing | GT wing | $1,299 | Ask us |
| G80, G82, G87 | AD-style wing | GT wing | $1,449 | Stands and hardware included |
| G87 M2 | CSL-style trunk V1 | Integrated trunk | $1,995 | Replaces the factory trunk |
The OEM++ is our best-selling spoiler overall. It’s our own design and runs the full width of the trunk lid, out to both corners. If your M2 is a CS, check with us first: the CS has its own carbon trunk lid with a molded-in ducktail, and the OEM++ is made for the standard M2 and G42 trunk.
Browse every style on our M3 spoilers, M4 spoilers and M2 spoilers pages. For a closer look at each car, read our G80 M3 and G82 M4 rear spoiler guide and our G87 M2 spoiler and trunk guide.
Fitment and install notes
Read each listing before you order, and follow the instructions that come with the part.
- Tape-on spoilers like the G80 high kick need no drilling.
- The G82 ducktail comes with predrilled holes and self-tapping screws.
- Wings mount on stands, and the AD-style kit includes them.
- A CSL-style trunk is a direct replacement for the factory trunk lid. The V1 listing asks you to contact us for shipping rates.
Our fitment guarantee: “If a part doesn’t fit the vehicle listed on its product page, contact us before installing and we’ll cover the return shipping for a refund or replacement.” Returns are accepted for 14 days on uninstalled parts. Painted or installed parts can’t be returned. Our 1-year warranty covers defects in materials and workmanship, and doesn’t cover accidents, impacts, road debris or damage from improper installation.
Frequently asked questions
Why is a car wing called a spoiler?
People often use the two words for the same thing. Even our shop files wings in its Spoilers / Wings category. Strictly, a spoiler “spoils” the airflow over the body to cut lift, a name borrowed from aircraft. A wing is an airfoil on stands that makes downforce.
Which is better, a spoiler or a wing?
For a street car, a spoiler gives a cleaner look, mounts more simply and keeps your rear view clear. A wing makes sense on track, where speeds are high enough for its downforce to matter.
Does a wing make a car faster?
In corners at high speed, the extra grip from downforce can help. In a straight line, a wing adds drag, which works against top speed. Porsche’s ducktail spoiler went the other way: it improved drag and raised top speed by 2.8 mph.
Is it illegal to have a spoiler?
The legal guide FindLaw lists adding a spoiler among modifications that are completely legal. Rules for other equipment vary by state, and anything that hides your plate number can get you pulled over. Check your state’s rules before fitting a tall wing.
Does a spoiler improve gas mileage?
Many factory spoilers on passenger cars are designed to reduce drag and help fuel economy. We don’t make that claim for our parts. We sell them as styling parts.
Do I have to drill my trunk to fit a spoiler?
Not always. Our G80 M3 high kick ducktail mounts with 3M tape, and the M2 MP-style spoiler needs no drilling. The G82 M4 ducktail uses self-tapping screws. Each listing says which method it uses.
Which should you choose for your BMW?
For a daily-driven M3, M4 or M2, a lip spoiler or ducktail gives the look with simple mounting and a clear rear view. Pick a wing if you want the race car look and accept the drag and the view. If you want the full CS or CSL look, a carbon trunk with the spoiler built in is the cleanest route.
See every option in our spoilers category and our trunks. Not sure which fits your car? Text us at 609-525-4865.
