People can hack into a car's microprocessors, "Stuxnet" happened, now we're told about "Stars" how safe are nuclear power plants ?

Did you know that cyber criminals can use the microprocessors in cars to disable, track or cause the car to malfunction?
Apparently so! Microprocessors, and there are a lot of them in modern cars… seem to me to be just waiting to be hacked. 
From what I can recall reading yesterday (!) horns have already been made to blast and cars have been disabled, and apparently it has been proven that the pressure checking system in the tyres can allow a car to be tracked, while I gather one of the universities managed to write a program which would disable brakes!!!
Now this is just cars.  Do you remember the Stuxnet story that came out about the virus being fed into the nuclear power plant in Iran last year?  O.K. well,  how many of you read the more recent update from Iran that they have been infected with another virus the call Stars.  I remember reading a comment at the time that  Stuxnet wasn’t that clever a worm and that it was probably masking an attack by much more efficient virus.
O.K. So as usual this sent me thinking… Like isn’t it a tad arrogant to assume that just because one or two countries together or separately, are capable of messing up a targeted nuclear power plant,  no one in another country or even the same country but with a different agenda, couldn’t have a lot of fun with any nuclear installation, cooling system or even waste disposal, just by sitting back and firing a few extra neurons and flicking a few keys? Especially if there were a bunch of guys who really enjoyed this kind of thing ?
Just wondered??

Source for car information http://cybercrimenews.norton.com/articles/car_computer/index.html