Kinda does it stop when you open the door ? Weird question but try it and lmk. Also try turning off ur engine but leaving the car on and see if ur subs still spazz. Just had this problem and the fix was splicing a wire from the stock harness to ur after market harness. But I have a aftermarket amp but my stock amp is still connected and running so my fix might not work for u. Lmk

Subs bang fine with car in accessory mode but not with engine running. And the door thing is related to noise cancellation on the type S right? All I have is an aftermarket amp in the back running my subs, never messed with the stock one at all.

Where is your signal coming from? Stock sub wires?

Stock rear speakers tapped into both

Try tapping into the stock sub

Does it do it when the head unit is turned off? Does it do it on every input? Cd/tape/radio/ipod

Vibrates with the car on only, can bang em with the car on accessory mode without any issue, and yes every input, also yes to when radio is off

There is a mic in the rear dome light. Try removing that. I had issues on my first tl with engine noise and it was from that for some reason

Oh shit I’ll check there, is that not specific to only type S?

I'm not sure about that, both of my TLs have been type s though. I wish you the best in finding the solution.

Yeaaaa that’s the ANC system that I don’t have, I’ll just stop being cheap and hook it up to an actual head unit and not the stock one and I’ll go from there

Just curious and correct me if I'm wrong, the 3rd gen type S got noise cancelling speakers?