It can be difficult to find the release button on some of the newer ones. The first time we rented a suburban with a foot operated parking brake it took me a good 10 minutes in the driveway trying to find out how to release it. Then last time it appeared to be completely electronic and set/released all by itself.

I have a semi-automatic at home (I think it's actually a clutchless manual) with flappy paddles and the handbrake is part electronic part normal hand-operated. It has a mind of its own. It turns itself on when you're stopped on a hill so you don't roll backwards, but it only seems to do it intermittently, which makes a hill start a bit exciting. Mrs T refuses to drive it, says she can't cope with the stress it causes her.