Despite some doubts, this product did exactly what it said it would on my RS4. Easy and quick to install, it works instantly. It does make a recognisable difference when the flaps are opened.

LOVE IT, ONE OF THE BEST UPGRADES

Easy installation and affordable! Great sound! Highly reccomended!

Works great easy to install love it 👍

I didn't really want to believe it but it's true. Rich sound, more robust but not too bad. I'm very happy to have decided to do it. The installation was done in less than 5 minutes. Super easy.

Works well on my 2023 SQ7, definitely hear that v8 through the entire rev range more so than without. A little fiddly as one valve is tucked behind a plastic water guard, but raise the suspension up and it helps get your hand in there.

Does make a louder noticeable difference even with the one valve

Great product and so easy to install ..now have full control over the valves on my f82 m4

Easy instal, easy to pair to the homelink, and best of all sounds great!

Honestly at first I couldn’t tell the difference then next day seems the car sorted it self out and now if definitely works, even used a endoscope to check a yep valve definitely opens fully . Now pops and burbles even in comfort mode , easy to fit 5 mins max just give the car a chance to sort itself out . Custer care was spot on answered all my concerns within 1-2 hours .

Really pleased no wires easy to fit great sound

Great device easy to install and does what it says on the tin, thank you for the quick dispatch.

Top 1A

Great addition to the car. Tone is much deeper and adds to the sportiness of the car!

Relatively easy to install and remove if necessary while maintaining all of the adjustable drive settings, unlike putting the fuse. The remote control allows for those full open early morning cold starts with the ability to dial back the aggressiveness for the sake of your neighbors. Also like being able to keep the exhaust fully open in 6 gear.