Tony's daughter wants a car stereo that will connect to her iPhone. Leo says that he can buy a new head end stereo, but it may be easier to just get a cassette adapter that will use the existing car stereo. He could also get an FM radio transmitter, but in the city, there's just too much congestion on the radio dial for that.
If he still wants to install a new stereo head unit, then Leo recommends getting one that doesn't have a physical adapter because the new iPhones have a new 9-pin connector now. He should also get a unit that supports A2DP stereo Bluetooth. He can then pair his phone to the bluetooth stereo and then it'll work wirelessly. Alpine tends to be on the leading edge, but almost any head in unit will do it now.