They call me Awesome!
THIS THING IS FREAKIN COOL!!!!
For $25 + shipping from Amazon, this is quite possibly the coolest car toy I've found.
Buy BAFX OBD2 Bluetooth scannner, plug into factory wiring harness, download Torque app, link it to your phone/tablet, and BAM you've got more data than you know what to do with.
It's got readouts for:
Ambient Air Temp
Intake Manifold Pressure
MPG (realtime and average)
Oh, and you can't forget that it's got the capability to read Check Engine lights and clear them. Literally one of the most usefull toys I've found so far. I LOVE this thing.