I am with you on this, some jack stands are so flimsy because the welding on them is terrible and the metal is too thin to start with. I never go under the car unless there is solid and stable wood blocks used, I give the car a good shake as well. Even with the set up I have just described I hate to go under the car as I find it too claustrophobic for my liking, I have a steering damper to fit still on the shelf to prove my point.