Is there an option which would allow me to plug my mp3 player in, so I can hear the mp3 recordings through the car speakers ?

 

Well what model and years you have ?
I have a 2008 LS, and it come with a AUX in
On the middle console, in the back you should have to RCA,
and to activate the AUX on the radio, you have to press the CD button for like 4 seconde, then it will go to AUX.

 

I was looking at 2010 SE, but didn't see any place to plug an mp3 in.

 

Im pretty shure they all have it
its just hidde, its not behide the Arm rest ? in the lower back on the right side ?
Maybe you dont have the port, i tought they all have it, i just hidden

 

It shd be inside the arm rest box, a usb port and the aux side by side. Mine is a 2010 LS though.