I had a Pioneer one (DEH-5550-MP) in my EF. Sound and featrues are great etc, but doesn't really help you with fitting in an AU. I have removed it from the EF as I am selling the EF.
BUT, I could be tempted to part with it if you are interested (New they are $599, I paid $470 odd, you could have it for around $350). I have the original box instruction manuals, remote and receipts (just prove it's not hot). Anyway, the offer's there, the rest is up to you.
A link to the Pioneer site is below: