l have an 07 Mercury Mariner Premier or Premium and l know you have to buy something for the mp3 player but is the car itself capable? please expalin and only answer if you know. thanks!

It is not the vehicle which has to be compatible, its the vehicle is stereo. Chances are you will need to buy a new deck so you can connect your MP3 player. Alternatively, you can always buy a play-through adapter which allows you to play your MP3 or iPod through the radio. l have one that plugs into the cigarette lighter that works very well, looks nice, and was inexpensive (less than $50, if l remember correctly)

Even if the car is not capable of it, you can still pick up one of those little FM transmitters that will play your audio over the radio.
http://amazon.com/s/ref=nb_ss_gw/104-2580076-6226351?url=search-alias%3Daps&field-keywords=fm+transmitter&Go.x=0&Go.y=0&Go=Go

Do you have an owners manual ? If so,it helps to actually read it. Read the chapter called ''Entertainment Systems''

Your system is already MP3 capable & you do not need to buy something else.

If you do not have a manual, or do not feel like going out to the glovebox for it, you can download here: https://web.msslib.dealerconnection.com/RightSite/getcontent/myfile.pdf?DMW_OBJECTID=09000c588058e6ef

the chapter you want starts on page 23

you can hook it up if it has a aux input jack