Yeah factory air purifier unit - has a control switch in the center console next to power mirror switch. Doesn't really do anything other than make some noise. Probably needs a replacement filter. Haven't seen it in any other E39A VR-4s yet, but have seen them in many other used imported cars from Japan - my old '82 GX61 Toyota Mark II Grande had one also. And no, I'm not pulling it out to sell!