for me there were 2 types of foams, the end near the cabin had a much more spongey foam and the other end was a thick white sponge, which made the sound a lot more noticeable after taking out!
Nice car. Have the same one in black. Took the sound generator out and removed the sponges... it made a difference but not until 5,000 rpm. Then it became too much and I put ihr back on.
took my foams out but in the process noticed the firewall cutout was still attached in the opening from factory .after removing this made noticable diference. may be worth checking out on yours fyi
The sponge removal on mine was truly transformational with the engine noise. Consider de badging the z4 on the rear mad the 3.0Si by the side, nice car!
Taking of the foam definitely makes a difference, you may have to check that your hose pipe are in good condition, I am on my second coupe, this is the only mod that I did to my car, the noise was too loud I had to put back one of the foam to reduce the induction noise. Go on the Z4 forum is a well known fact unless your vents or pipe are blocked.
Really wanting to get one of these cars but they’re So rare in wales though! Never ever seen one but really would like to. I need to see if I can even fit in one, they look really small and I’m 6ft2” and quiet big lol 😂 dieting and saving for when I can finally get one!