I have an infinity car, in the past 2 days i have been experianceing some strange issues. The speedometer keeps dying then the heat died and then the car died and would not start. The next day the same thing and today the car would not start at all. Does any body have any ideas? Please help the Garage wants a couple hundred just to see if they can identify the problem. I'm pretty hand with a wrench just need some help identifying the problem.

Thanks