Reaponse below. I was going to buy the one from tesla so i could ask them to install it for me. Can anyone tell me correct response to DS and parts team? Per my parts team, the HEPA filter for the Model S comes as part of an assembly that includes the mount. The part costs $200 + tax. I am not at all familiar with getting this part retrofitted however, my parts team did say that the HEPA filter takes an additional intake and cannot be directly replaced from the standard cabin air filter. If you are planning on retrofitting this, please provide the part numbers if available so that I can ensure the right parts are ordered. These parts do not include installation and are final sale.