Alright, I looked around here but I couldn't find anything to do with the Sony Dash, so here's my disassembly tutorial, which is hopefully the first of many that will allow access and customization of a device that has a lot of potential.
Flip the Dash on it's back, and locate the stiff sticker at the bottom
Remove it and locate the two screws underneath
Remove those two screws
The back of the Dash is very well disguised, but is actually just a glossy, stiff sticker that can be removed fairly easily. Do so, and locate the two screws underneath that sticker
Remove those, then use a wedge to gently ease the screen out of it's rubber shell
Once that's done, locate the clips and ribbon cables
Starting from the left, this is the speaker cable. If you're modding for an external speaker, this is where you want to be. Just push down on the top and pull back to remove it.
The second is the mic. To be honest I've never used it and I didn't even know this had one until I did this, but it will be an interesting tool when someone gets some homebrew running on this. Remove it the same way as the speaker cable.
The next is either touch screen, or display. Either way the latch is VERY fragile, and breaks really easy. To remove it CAREFULLY pull the brown latch up, and pull out the ribbon cable.
If you figured the last one was the touch screen, then this is the display and vice versa. This one is a little more robust then the last, but still be careful with it. Gently pull the tabs on either side up to release the cable.
Locate the three screws holding the board in.
Remove them. Now inserts a wedge under the board and gently wiggle it until it's free.
Underneath that you'll find a silver plate. Locate the two screws holding it down. Once you remove those you can remove the antenna, and the speakers.
[img]http://jacobsbin.webs.com/Images/dashtuts/disassembly/Step6.JPG
Congratulations, you've disassembled your Sony Dash! Now get to work on those mods!