When you say they took you player, tuner AND sled, this makes me think that :
1) the thief knew what he was after.
2) since these things are hardly common (especially the tuner), the thief probably KNEW that you had an Empeg in your car.
With this I mean that you possibly have met the thief and know him.
Have you met any persons lately whom you told about/shown you Empeg to and that seemed more than mildly interested?

Also I can see in this picture that there are some grease stains on the right hand corner where the sled was. It's possibly a fingerprint belonging to the thief that he made while pulling your sled out.
Same goes for that LCD screen. If the thief has touched it, his prints will be all over it.
My advice is to go to the police and have them dust you car for fingerprints.
And if they find prints, then keep you fingers crossed that the thief is already known in their prints database.

I'm very sorry about your loss. I hope this helps somewhat.