Long time lurker, just wanted to give you guys a heads up that the lenovo wireless multimedia keyboard/trackball is on sale for $30 shipped.
I bought this device a few months ago for slightly more (it's usually on sale <$40). I haven't yet put together my car PC, but I bought this device specifically for car PC applications, but it is very popular for HTPC use. It's not BT, but I think this is actually better for car PC applications. The trackball is slightly awkward, but I imagine most are using a touch screen, so that might be a moot point. The keyboard is relatively tactile, much like an HTC phone's keyboard.
I'm a big fan of DealExtreme, as well, but i think this device makes more sense than the BT keyboards sold on DX.
Just a heads up for those who are looking for a good input device.
I'm not sure if this belongs in another sub-forum, but besides the classifieds, I didn't really see a better/more appropriate space. Feel free to move as necessary.