Before you order a carbon grille for a G80 M3 or G82 M4, check for the front radar that Active Cruise Control uses. Whether your car has one decides which grilles can go on it, and it only takes a quick look to check. You’ll also need to move your M3 or M4 badge to the new grille without damaging it.
Key takeaways
- Only some cars have the radar. In the US, it comes with the Driving Assistance Professional Package (option code 5AU), which is offered on automatic Competition models. A manual M3 never has it.
- The radar sits at the bottom inner corner of the driver’s-side kidney, which is the kidney on your right as you face a US car.
- A radar car needs a grille that leaves the sensor uncovered, like our CSL style with radar. Bars in front of the sensor block it.
- The radar is unplugged when the front bumper comes off for a grille swap. Afterward, run a sensor calibration if iDrive asks for one.
- Your badge moves over with gentle heat and fresh automotive tape. Our grilles don’t come with one.
What the front radar does
The front radar measures the distance to the car ahead. It lets Active Cruise Control with Stop & Go hold a gap, slow down and follow traffic on its own. On the G80 M3 and G82/G83 M4, the radar comes with the Driving Assistance Professional Package. BMW lists the package as two options: 5AU (Active Driving Assistant Professional) and 5AR (Extended Traffic Jam Assistant).
In the US, the package costs $1,700 and is only available with the automatic gearbox, which means Competition models (BMWBLOG, 2025 M3). Every M3 and M4 has cruise control and frontal collision warning as standard, so those don’t tell you whether your car has the radar.
How to check if your car has the radar
Look at the grille
Stand in front of the car and look at the kidney on your right. On a US car, that’s the driver’s side. Check the bottom of that kidney, next to the center of the grille. A car with the radar has a flat black panel there, covering the lowest bars. If you can see between the bars at that spot, there’s no radar.
Check the options
Your window sticker lists the Driving Assistance Professional Package if the car has it. On a VIN decoder that shows factory options, look for 5AU and 5AR. A manual M3 has no radar, so if yours is a manual, you can stop here.
Try the cruise control
If your cruise control holds a set distance to the car ahead and brakes for slower traffic by itself, the car has the radar. If it only holds a speed, there’s no radar.
If you’re still not sure, text a photo of your grille to 609-525-4865 and we’ll tell you which one you need.
Which grille does a radar car need?
A car with the radar needs a grille that leaves the sensor’s corner open. BMW’s own M4 Competition grille, for example, comes with a cutout for the radar (51138081142) or without the cutout (51138081141). BMW’s genuine M4 CSL grille has no cutout at all.
Here’s how our carbon grilles line up:
| Grille | Car with radar | Car without radar |
|---|---|---|
| CSL style, with radar | Yes | Ask us |
| CSL style, without radar | No | Yes |
| GT style, two-piece | No | Yes |
| GT style one-piece, V style and GTS design | Ask us | Yes |
The with-radar version leaves the lower half of the driver’s-side kidney open, so the radar can see out and Active Cruise Control keeps working. The other kidney has the same bars as the version without radar. Our carbon grille guide compares every style side by side.
What happens if a grille blocks the radar
If solid bars sit in front of the sensor, the radar can’t see through them and Active Cruise Control stops working properly. The grille itself has to leave the sensor uncovered.
The front bumper comes off for a grille swap, and the radar is unplugged before the bumper comes away. Brackets on the old grille move to the new one, and once the bumper is back on, you run a quick sensor calibration if iDrive asks for one (Horizon Motorsport install guide). If the radar gets knocked, or Active Cruise Control shows a warning that doesn’t clear, have a BMW dealer or a shop with radar calibration equipment check it.
We don’t recommend cutting bars out of a grille made for cars without radar. It’s hard to get a clean opening, and you can’t return a part once it’s been cut.
How to move your M3 or M4 badge
Your model badge sits on the top bar of the driver’s-side kidney and moves to the new grille during the swap. Our grilles don’t come with a badge, so you’ll reuse yours.
Badges are held on with adhesive. To move yours without damaging it:
- Warm the badge gently with a heat gun on low or a hair dryer to soften the adhesive.
- Ease it off with a plastic trim tool or a length of fishing line. Don’t pry against the paint or the badge’s face.
- Clean off the old adhesive with an adhesive remover that’s safe on plastics. Avoid acetone, which can damage paint and plastic.
- Apply fresh 3M automotive double-sided tape, cut to the badge’s shape. Line the badge up before you press it onto the new grille’s top bar, because the tape grabs right away.
Parking sensors live in the grille too
The front parking sensors sit in the grille’s horizontal band, which is why our carbon grilles have two round openings in it. The sensors and their rubber grommets move from the old grille to the new one. Seat every grommet fully, because a sensor that isn’t seated properly can give false warnings.
Our install guide covers the whole grille swap, from taking the bumper off to putting it back.
Frequently asked questions
Do all 2021 to 2026 M3s and M4s have the front radar?
No. Only cars with the Driving Assistance Professional Package have it. In the US, that package is only offered with the automatic gearbox, so a manual M3 never has it.
Is the radar in the same place on a 2025 or newer car?
Yes. BMW kept the same grille for the 2025 update, and grilles made for radar cars fit both the earlier and the updated cars.
Can I fit a closed grille if I never use Active Cruise Control?
You’d lose a feature you paid for, and the car may show driver-assistance warnings when the radar can’t see. We’d recommend the with-radar version instead. It costs the same and keeps the system working.
Does a with-radar grille look different on the car?
A little. The lower half of the driver’s-side kidney is open, so you can see the radar panel behind it. The other kidney looks the same as on the version without radar.
Will my parking sensors work with a carbon grille?
Yes. Our grilles have openings for them. Move the sensors and their grommets over to the new grille, and seat the grommets fully.
Before you order: a quick checklist
- Check for the radar using the grille, the window sticker or the cruise control.
- Order the grille that matches, or text us a photo first.
- Plan the install, since the front bumper comes off for a grille swap.
- Have 3M automotive tape ready for your badge.
Then pick your style in the carbon grille shop. If a grille doesn’t fit the car listed on its product page, contact us before installing it and we’ll cover the return shipping for a refund or replacement.
