a few questions about my audi

i have a 1996 a4 im wondering if a key set from a  1998  with  work if i replace all the tumblers and inginition switch  i dont trust the seller  so i want them  changed as well as  im missing one of them. also as well as i have the standered stereo with the volume knob on the left and the casset player just wondering if thats cabitable with the audi alpine 6 disc cd changer since it came wiht the car but not installed.

bump also no question about the stereo just the locks

dude if the guy you bought your car from was that weird that you think he is gonna steal from you and you need to change your locks on your car thats a flag to find some1 else uness your geting it for free.....

each car has a diff key pattern. you would have to change the ign switch, locks and reprogram the new key. and like got2speed said, look for a diff one if you don't trust the seller that much.