> you should be aware of its whereabouts at any given moment

Says who? If the car is mine, I am free to do with it whatever I like (of course, excepting criminal acts). I do not owe anybody an account of what I - or the care - did at any particular moment. If the car was used in the commission of a crime, it's up to the prosecution to prove I had something to do with it. If they think I know who did it - prove it and prosecute me under the law. You can't just prosecute because you think I should know, that's not how proper law works - otherwise every cop in the country would be 100% sure who they caught is the criminal - because why not, if it's enough for conviction, why work harder!

> If someone shoots a person with your gun, you gonna say it wasn't you and expect them not to question any you further?

They can question all they like, but to secure a criminal conviction, they must prove, beyond reasonable doubt, that I was the person who did it. Otherwise you get no conviction. If they strongly suspect I did it, they would find a proof - but the fact that I owned a gun is not that proof (for one, guns can be easily stolen, and frequently are).