Here's my story:
I used to work for a tire manufacturer and every year we would hold an even at your proving grounds to show off our new products.
One of the events was demonstration about what happens when you only replace 2 tires and where they should go.
We had 3 identical cars. One with 4 new tires, one with new tires on the rear, and worn tires on the front, and one with new tires on the front, and worn tires on the rear.