I honestly have no clue if that digimoto interface will work with the plugin. It was designed to control an ELM. If the digimoto can be controlled the same way then it'll work fine otherwise you would be out of luck.
In response to the speed issues i'm working on doing some interpolation of the data so it appears as if its coming in much faster to the end-user. This means smoother gauges and faster updates. I've found a code sample from another mp3car user where this was implemented so i'm thinking it shouldn't be too hard to implement his ideas into OBDMPG.
I was also wondering if everybody was fine with the current mpg averaging, meaning a trip and an overall average. I've been trying to think of the best way to obtain useful data and thought adding something like a 5sec average might be useful. If anybody has any thoughts please let me know.
I'm going to be kinda busy this week and the beginning of next week since its finals time for me but I should be able to make some serious progress over my christmas break and squash a lot of the existing bugs.