Having seen one of the member's idea of placing a GPS into the storage box on the dash, I tried to fit my existing GPS (a Kogan unit), but it was too big, especially if I wanted to close the lid with the GPS inside.
Good guys have a special going for a Garmin Nuvi 1260 for $119. It fits the box very well and runs rings around the Kogan GPS, so I bought one. It has some basic trip computer features. You can put in your average fuel consumption in and out of town and the fuel price. Not sure what exactly will it return as I have not yet driven with the Garmin running.
The interesting bit (and the reason for this topic) is the
ecoRoute HD. This thing is an OBDII bluetooth device that can store 29 hours of data for diesel cars and 40 hours for petrol. Pair it with your BT enabled Nuvi and presto, you get real time data from your engine management, trip computer function (sorely missing from my SX) a variety of gauges, engine diagnostics etc.
After some research I found that this add-on is a hefty $199 here in Oz, but sells for around $86 on Amazon. To get around Amazon's "no shipping to Australia" policy, I got
priceusa.com.au to get a quote for me. These guys have agents in the US who buy on your behalf, ship to Priceusa in Bendigo, Vic, they then mail it to you.
I should get a quote tomorrow and will be happy to update this thread if there is interest how this GPS come trip computer will work out.