I have done what you folks do regarding lift points. And I to have a Sam's Club jack. To support the car, I cut 4 pieces of 8" long thick walled 3/4" diameter pipe and bent each (in a 12 ton press) at the mid point to an angle of about 10 degrees. I stuck one end of the pipe all the way into the angled jack holes of the car, and then placed the saddle of the jack very near to the car so that when the car was lowered, the protruding pipe nestled into the saddle. Seems to work great. Its very stable and can't slide off. The only uncalculated factor is the sheer strength of the 3/4" pipe and, while this is not very scientific, judging from the amount of pressure I needed to bend the pipe, I have problems believeing that's a risk. Even the 1/4" lag bolts I use have a sheer strength of 2,995 pounds. I think this sounds safer than simply having the car sit on top of the jacks with the jacks under those foam or rubber blocks.