I have been using jack stands bought from Sears and home made wood ramps: If the car is on the wood ramps, I put the jack stands under the side railing and the engine as backup. If the car is on the jack stands, I put the wood ramps under the engine as back up: This setup seems plenty safe for me to crawl under the car but my wife still thinks everything will fail and I will be crushed under the car. Is there any chance to convince her otherwise? If so, how? Or is it indeed dangerous as she thinks? I heard cinder block (or concrete?) can disintegrate in an instant but could 3 layers of 2X10 wood split simultaneously all of a sudden? Or can the weld point of the jack stand fail all of a sudden?