Hello Elchgemeinde, according to an offer at ebay every diesel car should already have a heater installed and must only be unlocked for alleged 750 euros with the friendly one. Here is an excerpt of the ebay display:According to Volvo price list this Euro 750.- …I tell you here how they get this for about 90.- Euro …..very simple….any Volvo diesel car, whether the 60 he ; 70 he ; 80 he or 90 he series has already installed this, look at front left under the mud wings ( at the XC 70 ) you should find the exhaust hose of the heating… instead of spending here Euro 750.- at Volvo I tell you how you can save here about 650 Euro…the heating only has to be unlocked…. this can only be a Volvo dealer and that takes you as stated Euro 750 .- off….or you offer here and learn how it is different…this is quite legal… I find this quite strange, because I would offer a hint and then possibly have to drive hundreds of km n… Is there any experience with this alleged “unlocking” of the standard built-in heater? Do you need additional parts? Greetings to all of the just over 150000 jumped Silbertdi 😉