Another user with a block of wood. I have a 4x4 and a bigger chunk of what I am assuming was part of a rail road tie in its past life. Have also used the front tires if I have those off.
I’ve used wheelchairs for years, and I wouldn’t want to park without them. They’re a simple but effective way to keep everything in place, whether working on a car or just parking on a slope.
I used to coach wakeboarding to the physically disabled. We got super drunk one night and were doing wheel chair wheely contests in our friends chairs... kept hitting something and looked down. It was my buddies legs, I was running him over. He said "It's cool, I can't feel them anyway"..... wheel chair chocks