kylej - I love your gps placement, I will see if my suction cup thing fits there , need to run a line to it though.

the garmin is a dedicated piece of instrument, I spent my money instead to get back light guage that can read realtime engine information, i can monitor more datapoints than garmin,
but the cons are, the display is small, and does not have mounting feature,

I got it to monitor engine temp and how long it takes to reach 170s F, so I can take it easy before I go up to 6.x k rpms.

 

I know this is an old thread but I just thought I'd mention that the EcoRoute HD dongle can be used without a Garmin GPS. It can be used along with an app for Android phones called Garmin Mechanic. Too bad it isn't available for the iPhone.

 

i use ecoRoute on my 370Z with my Nuvi as my extra gauges. works very well.