Exactly. If a manic depressive is holding drag races with your car, or shagging his underage girlfriend in the back seat, the TSA is not an issue. In fact, the involvement of a valet would create serious problems with a prosecution, owing to their unreliability, total disrespect for documentation, and confused chain of custody.

And those people are not bound by a little thing we call 'the bill of rights'. Moreover, if you find out that happens, you can quit using that valet service. You can tell others that that valet service is crap, and they too, will quit using it. There is a generally easy 'opt-out' of the valet service. Not so much with your country.

You cannot opt out of crazy valets at airports. One company captures the parking concession, hires the cheapest (i.e., crappiest) valets they can find, and said valets do appalling things with/to your car.

So now after they finish joyriding, if they are not too hungover to remember, they leave a TSA card to keep their boss from bitching at them. Theoretically that card is an incremental infringement of your liberty, but in practice you have already been reamed out so hard by the valets that you won't notice.