After living with the current state of-the-art in Prius add-on instrumentation (The ScanGauge II), I eventually became frustrated with it. What really bothered me about the ScanGauge is the slow update frequency, and the lack of any type of analog display (meter type or bar-graph). So I decided to take on a project of building my own. Here's what my current attempt looks like so far: It uses a very bright LED backlit LCD with more resolution than the ScanGauge and is easier to see in all light levels, even with sunglasses on. It automatically detects when you turn the lights on and dims the display for night use (as shown). The picture shows as I normally have it configured. The bottom line is showing a definable analog gauge in the form of traction battery amps. It has a resolution of 100 pixels and when set to amps it scales to a +/- 100 amps. It shows Charge (regen) amps by "growing" from the left side and discharge (driving) amps (as shown) by starting on the left side. It's surprisingly simple to read at a glance and since the screen updates at around 10 times per second, it's nice and fluid and enables you to really get useful information fast. The same amp figure is also shown in digital form just above (3rd line) and center. This way you can have a fast reading analog bar-graph as well as a precise digital readout all at the same time. Other than engine temperature and mode on the top line, The other items shown in this example are mainly information about my PHEV, such as mode, spoofed SOC, Amp-Hours, real SOC, Pack voltage, amps, and temp. The updates are so fast that the camera actually caught the amps changing from 1.0 to 1.1 in the same frame! Many of the faster passive parameters are actually averaged and slowed down somewhat so the display isn't a twitchy blurry mess. Each of the 4 lines of the display can show many parameters, up to 3 per line as a digital readout or 1 per line as Analog, similar to how the amps are shown. I can also split the line with an analog bar-graph on one side and the digital value on the other, but I didn't like it as much. It also includes an audio annunciator that can make many different kinds of alarms and alerts. I have it programmed to make a short but quite audible beep on EV mode change, as my 2008 only beeps (3 beeps) if EV mode is canceled. It makes a high pitched beep on successful EV mode enable, and a low pitch when deactivated. It also makes other sounds to alert me to particular mode changes that are specific to my PHEV. It can read and reset ALL Prius DTC's, not just the few the ScanGauge is limited to. I'm still evolving the user interface, but as of now it meets all my needs, including display and adjustment of custom modes and parameters from my PHEV. I recently ordered a higher resolution graphic LCD display which I hope to implement sometime soon which will give me a much nicer looking display with more area for Analog gauges. I also read most of my Data passively from the CAN bus, so there is no lag and no interference with anything else that may be on the bus. When the car shuts down the system automatically goes to sleep. It will automatically power back up when the car is turned back on or (in my case) when I plug the car in and the custom BMS wakes up. This way I can monitor my charge; battery SOC, Amp-hours, Temp, Voltage, Amps, etc. I've received a lot of interest in this so far, so I'm considering offering it as a kit initially, and then maybe later as a fully developed product. Right now it only works with a Gen II, simply because that's what I have. If I can find someone nearby with a Gen III that wants to work with me on development, I hope to have it working on it as well at some point. I'd like to solicit comments and ask everyone's ideas for features they'd like to see included. This will be a Prius-specific device, not a generic one like the others on the market, though it's possible a future upgrade could add more functionality. I plan on including a PC interface so it can easily be upgraded and configured, and customization will be much easier this way rather than spending hours entering hexadecimal with 3 buttons. My main user interface is a rotary encoder (knob) with built-in push button, so it's easy and fast to scroll through different modes and options. I've also recently obtained a higher-resolution graphic LCD display that will enable even more detail and more analog-style gauges. But even in it's current incarnation it's still way more useful than anything else I've had. I realize there is a lot of activity in this area, and lot of prior art. Norm's Canview was the ultimate, but it's costly and complicated. I simply don't need that much information at once, and if I add an Extra LCD that big, I'm probably just going to lose it along with a window some night. There are also a lot of people working on smartphone versions, but I don't like this route either, as it requires setting up my phone everytime I get in the car, and then I have an even harder time using it for Phone/Nav/Music. It's already annoying to share one small screen for those 3 functions, so I didn't want to add yet another! The hardware cost is likely under $50 even in low quantities, But I haven't priced everything yet. (I already had all the components laying around) I have it installed over my rear-view mirror. It's easy for me to see and reach there, yet not in the way, and it's hard for others to see when I park my car in a questionable location. I ran a twisted pair cable from the CAN Bus connection at the Power-steering ECU up to the mirror, and it uses the same style (RJ-45) connector as the ScanGauge did, so it's backward compatible. It just slides in, so I can unplug it in seconds and take it out, leaving only a short RJ45 tail. Questions? Suggestions? Comments? Ideas?