Horse 1927 - The Most Expensive Motor Accident Ever

The Goodwood Festival of Speed (which is a romp around the grounds of the British Automobile Racing Club's President's estate) is probably the greatest annual historic motor show in the world. Every year, priceless machines are thrashed about the grounds and sometimes it ends in bent metal. Invariably when one of these things crashes, the question posed in what is the most expensive car crash ever?

Ever since mankind invented the greatest machine of all time, the wheel, we've gone practically everywhere and at great speed. We've raced chariots, trains, and since the last decade of the nineteenth century, the motor car. Usually it is race cars which push the boundaries of technology and if a race car crashes, especially a Formula One car, then the repair bills can be substantial.

For most of us though, because our motor cars are the second biggest capital asset we're likely to own, they also represent some of our biggest repair bills. Even on a cheap family hack, a small accident might run into thousands of dollarpounds to repair.

There are also costs in retrieving a motor vehicle though and for this reason, I think that this would be the most expensive motor accident ever:

Nope. It wasn't just enough for us to go to the moon. We had to take some cars up there so that we could drive around. Seriously people, you're on the moon! Isn't that far enough?

In less than 23 miles of driving, the Lunar Rover suffered the first extra terrestrial motor accident. Just to prove that even when it is rocket science, people will still klutz it up, Eugene Cernan accidentally broke the fender on the Lunar Roving Vehicle of the Apollo 17 mission with a hammer handle, when he dropped it. They tried to tape it back on but the tape wouldn’t hold because of all the dust on the moon. It turns out that duck tape isn't as almighty as we thought. Still, a kludge was worked out with some clamps, and a map which they found inside the Lunar Module; those bits were later removed.

If you divide the cost of the Apollo program by six (being the number of missions that actually landed on the moon), then you arrive at just under $5 billion per mission in 1970s dollars.
If inflation has been running at 4% (which is an historical average since the beginning of the Roman Empire), then the estimated repair cost in 2015 of that one fender is about $30 Billion. Most of that is simply getting there.
Probably a new fender would only cost tens of dollarpounds to fix at it's only cheap plastic but once again, we're forced to pay some licensed bandit with a tow truck to take the car to the repair shop (in this case NASA and another Apollo style moon mission). Or in this case just abandon it.