My sister has an xA and has been wanting XM radio for a while. My parents did not buy the XM radio option when they bought her the car, but the radio says its XM ready. My question is, will I beable to install the Terk XM Universal Tuner (XMDirect) into her car? If I buy the tuner, will I have to buy anything else to aid in the install? I did I search on this, but I could not find a definite answer.