Careful with the car analogy. It is indeed no small task for sober responsible people to operate a motor vehicle. They have to pass written and road tests. They must register the cars and have proof of insurance. Gun owners are not held to nearly as high a standard when it comes to a demonstration of responsibility.
There are allot of folks who have a license that shouldn't be driving. Look at any meth/crack head, any alcoholic, certain senior citizens or any teenagers whose parent bought him/her the fastest car on the lot and turned them loose on society with little or no driving experience, even though they all passed the test.
Bottom line is guns don't kill people, guns in the hands of irresponsible people do.