2012 HU removal

I want to install a subwoofer in my 2012 Prius II and get the signal feed from the rear speaker outputs from behind the touch HU. However, I'm having a problem removing the HU. I have removed the four 10mm bolts, but the radio appears to be stuck. I can not pull it out. I have tried rocking it back and forth while pulling forward, but to no avail. Is there something else I need to loosen or remove?

Having read nearly all of the related threads, I came to the conclusion this would be an easy task. I am probably overly cautious not wanting to break anything, but I am at the point where I need some advice from the experts.

Thanks

 

Update!

To remove the HU from my Prius I had to use the same techniques used for removing the trim Pieces. My expectations were that the HU would practically fall into my hands once the four bolts were removed. Well, I was wrong. There were tabs attached to the front Etschusion of the radio, which snapped into mating receiving holes on the dash assembly.

[FONT=&quot]This is probably familiar to those who have previously removed their HU. However, I spent many, many hours searching the Internet and did not find much specifically dealing with the 2012 (The procedure might have been in the details somewhere, but overlooked.). Anyway, if this helps someone else, good.[/FONT]