So, this man on YouTube rescued a 1970 Cadillac Sedan DeVille (Jack's was a 1969). The car had sat under a tarp at the bottom of a pasture for 20 years. The bottom was rusted. Water had seeped into the car. It wreaked!
Outside, however, it looked amazingly well. Oh, there was evidence of rust and pitting, but it was very little, considering. The halo roof (vinyl) was still partially intact. The head lights and tail lights were intact, although the left rear reflector was broken.
Under the hood, things looked amazingly well. Oh, some wires were loose, missing, or worn. The fluid levels were low. All in all, it looked much better than one might expect. The man bought a handful of parts, put them on, raised the fluid levels, and started the car. Oh! He did have to replace the tires -- no surprise there.
So, he managed to get it to the gas station before it ran out of the five gallons he had put in from a can. Then, he set out on the interstate, where he took the car to 80 miles per hour! Can you believe it! But, then, he ran out of gas. The way he figured it, he had gotten 4-1/2 miles per gallon. That's about right, since fully tuned and operational, he would have gotten between 5 and 10 miles per gallon. They don't call 'em land yachts for nothing.