Just when I thought I had every upgrade I needed, a co-worker who has a 5th wheeler told me about this little neat thing for your tow truck:
It plugs into your diagnostic port and can read and translate any vehicle code BUT it does SO much more like link to a smart phone (with WIFI or Bluetooth) and, with an app on your phone, you can monitor a huge amount of real-time info on your truck. (Temperatures, fuel economy, RPMs, pressure, etc.)
My main concern was if the thing needed to be unplugged or can you turn it off when you aren't using it and the documentation said it goes into sleep mode after 5 minutes of not being used and has a button you push to turn it back on.
Only $69 on Amazon and my friend said the app he got for his Droid was free but he spent the extra $5 for the full version and he has many more features.
So I'm buying one...hopefully my last upgrade! (Yeah, right...)
Oh, here's the link to their webpage: PLX Kiwi 2 Wifi | OBD2 OBDII iPhone