How do i find out what should of been in the car when i bought it (cd inter changer)?

Hi in the instruction manual it says cd inter changer and sat nav the car was bought at a garage and it has a previous owner not all instruction manuals are for that Pacific car i know depends on the model so how do i find out i dont want to buy a cd sat nav thing if its no good for the car many thanksHow do i find out what should of been in the car when i bought it (cd inter changer)?I googled window sticker look up and found a site where you enter the VIN and it shows your original window sticker. This was a ford though and in the US so I'm not sure if it works for Peugeot.