ive had the ignition problem. i think its caused by forcing the key to turn over while the steering wheel is locked. since ive replaced mine ive noticed somtimes it seems to be binding. all i do is rock the wheel a little and then the key turns right over. havent heard anything wrong with the auto trans?? and as far as after market stereo goes its the same as any other car. and plenty of people on the forum have aftermarket headunits and subs just check around!