I am the one who was looking at the idea; I was going to be monitoring ODB-2 data over an adapter to serial and displaying it on the empeg screen. There are a number of delays on it, and I have done no further work in several months now.

It's not impossible; the serial protocols are published in a number of places, and it is basically a non-polar 5V serial diff connection. You can buy ODB to 232 adaptors all over for relatively small money. The major problems are that you must process and display on the fly (in RAM working - interferes with the player) since the disks are mounted RO at startup, and you must co-operatively share the screen with the player to display any stats, either graphically or otherwise. Otherwise you have to stop the player, and allow your app full control of both memory and screen. It really is not worth trying to write data to disk and risk a head crash while active.

My current approach is to look at a small footprint, high perf JVM with AWT graphics for the display part, but I have no co-operative solution operative.

Have a look for previous discussions about data acquisition and display on the empeg, and other threads on ODB with the search mechanism.