I'm afraid that mine aren't nearly this pristine. I played with mine constantly. I usually ended up drilling the rivets out of the cars so I could build mini roll cages for them after I cut out the passenger seats. - And of course, I did the obligatory re-paint to turn them into stock cars. Many of my trucks were converted into car haulers.
I did keep some of my Hot Wheels in better shape and some of them I still keep in one of those old Hot Wheels collector cases.