what do i need to plug in to my computer to fix cars?

Solution
The best software that I know of and that is used by many certified auto mechanics is "ALL DATA". I have used this and it is very comprehensive. It covers almost all cars on the road and the DVDs are updated on a quarterly basis. The license is expensive.

More info: http://www.alldata.com/
The best software that I know of and that is used by many certified auto mechanics is "ALL DATA". I have used this and it is very comprehensive. It covers almost all cars on the road and the DVDs are updated on a quarterly basis. The license is expensive.

More info: http://www.alldata.com/
 
Solution