Check out this wireless gadget from Mavizon to be launched next year. The dongle is inserted in your vehicles OBDII port (sorry pre-1997 car owners you probably don't have the port). It is GPS enabled and sends to your iPhone oil levels, maintenance records and other diagnostics that are tranlated into English. The gadget also allows the car's GPS location to be sent to the phone, or any other numbers you program and will summon emergency services in an accident. All this (hopefully) for less than $300!!!
[Source: Mavizon via SlashGear via Gizmodo]