The changer in your 99 is most likely an alpine. Becker's changers are rare in those cars after 93. The head unit probably is a Becker though. Becker does have a single cd plug and play radio that has the ability to accept an auxiliary input. It looks close to OEM and is a popular upgrade from the tape units.

Here is a picture....



Here are the specs...

http://www.beckerautosound.com/4602specs.html2