Mini-guide: Cheap (<$25) AUX port to replace stock head unit.

[Drake]

bluetooth obd2 port and a such would allow a speedo and tech with the right ap.

The "Torque Lite" application I use can handle this part.

i haven't found anything to make it the "key"

Have you looked into bluetooth remote starters? That is the first thing that comes to my mind.
A quick search brought up this, but I also saw some comercial offerings that may be easier:
Remote Car Starter using Bluetooth