how to connect the A4's radio ?

["R. Wiratorn" <withu@loxinfo.co.th>]

        Hi, I'm going to change the radio of my A4, I have some questions as
following

              1.  How can the radio be connected to ignition switch so that
the radio
                   will turn off when the ignition is off ?
             
              2.  Which fuse should be use for the radio ?
             
              3.  Is the fuse no. 37 controlled by ignition switch ?

        The OEM radio can be to turn on all the time regardless of ignition
switch position,
        which I always forget to turn it off.

                                                                        K.Ben