The AMP steps have pinch-proof and anti-jam overrides. Pretty slick set up. If you want to drive with them down or wash them you just leave your foot on top until it tries to close and then they stay down. I have not hit a curb yet.
I also use them in -40c here in Canada and they work like a charm.
One more thing to consider, they have a wicked warranty program and the best customer service I have seen in the aftermarket world. I had to remove mine from my F350 that was totalled and they sent me, free of charge, all the mounting bolts/hardware/instruction to sell them as close to new as possible. They also threw in 15 stickers! Gotta love them stickers!