I don't have a tape player in my car though. I just have a cd player. can I still use this tape player device

Your question is a little hard to understand - what exactly do you mean by ''tape player device''?
If it is something that fits into a tape player, then you obviously can not fit it into a CD player.
On the other hand, if it is an FM transmitter for an i-pod, it works through the radio, not the player.

More details would help...

kristin this wo not be to hard.. Like the other person mention u could get an FM transmitter. lets break it down

An Fm transmitter does what it says, transmits to an fm station..

do u remember the old walk mans that played cassette tapes? well u can get a cassette tape player an hook up an FM transmitter to it an it will play through ur car stereo

http://germes-online.com/direct/dbimage/50307542/FM_Transmitter.jpg

there is a picture of an fm transmitter.. u can pick one up cheap from stores like bestbuy an circuit city. u might even get lucky at walmart