If I were James Bond, I’m sure I’d want an Aston-Martin Vantage V-8, because it might give me the edge in escaping from the bad guys in a Mercedes S-Class. Plus my life expectancy wouldnt be great if I were James Bond, so I wouldn't worry about residual value after three years.

But most of us do trade in or sell our cars eventually, and buying a Ferrari or Lamborghini isn’t like buying a Picasso. Some appreciate (lucky are those who bought an AC Cobra at the right time, then hung on to it) but most don’t. In fact, they lose value faster than most other cars. Pardon me for having a thing about supercars — here I wrote about them being owned by dictators and playboys, and getting confiscated. Here I wrote about them as the most expensive cars in the world.

For $219,500, I can buy a 2008 Lamborghini Murcielago LP640 with just 2,458 miles on the clock. That’s not bad, but new it was at least $313,000. So let’s see, we’re down $93,500 here, and each mile driven cost approximately $38. Cheap at the price, you say?

Supercars are famous for not being driven much — they’re glamorous garage queens. How about a 10,850-mile 2003 Ferrari 360 Spyder for $85,500? New, that car was $165,986, and that’s just the base price before any extras. We lost more than $80,000 of value there, approximately $8 a mile. The NADA price guide tells me average retail for this car is $91,400 today, so maybe it’s not quite that bad.

One more example: A perfectly presentable 1999 Rolls-Royce Silver Seraph with 55,000 miles for $39,000. And it's a much nicer color than the example above. It was hand-made in Crewe, England, gets 12 mpg around town, and debuted in 1998 at a price of $220,695. How the mighty have fallen! We’re down $181,695, and each mile driven cost $3. At least the owner got some use out of the thing, but its next life is likely to be as a wedding car.

Of course, before you get all upset, I know there are examples of expensive cars hitting the stratosphere down the road. Twenty years ago, I had the opportunity to buy a barn-find Mercedes-Benz 300SL Roadster from Dragone Classic Motorcars for, if memory serves, $30,000. And here's one in Hemmings for $799,000. But I've got to ask, just how lucky do you feel?

Just for fun, let’s compare these results to that of a typical Toyota Prius. A 2010 model like the one below started at $21,400. A rough average of 2010 cars I see advertised is around $18,500. We’re down only $2,900. And that’s why I’d probably buy a Prius new, because they retain their value so well.

It's possible to come out pretty well with a used car. Edmunds.com just went through a sub-$5,000 "debt-free" car experiment in which they bought a '96 Lexus ES 350 for $3,800, drove it 18,000 miles, then sold it to an employee for $2,668. It only broke down twice.  The general experience was positive.

To make money buying cars, you really have to anticipate what might be valuable 20 years hence. Here’s one you might want to take a chance on — the Tesla Model S. Buy one now with a $10,000 down payment through Tesla’s new buy/lease hybrid plan, and you’ll have one of the first 10,000 cars on the road. It’s guaranteed — by billionaire CEO Elon Musk — to have after three years “the same residual value percentage as the iconic [and aforementioned] Mercedes S Class.” That’s currently 47 percent of the new price, according to Kelley Blue Book. If it isn’t worth that much, Musk guarantees the difference. How can you lose? Even my minister wants to buy one.

No, forget I ever encouraged you on this, there are lots of ways you can lose. Maybe you should buy a Picasso instead. But it doesn't cost anything to just look at supercars, and here's a bunch of them in a traffic jam in London:

The opinions expressed by MNN Bloggers and those providing comments are theirs alone, and do not reflect the opinions of MNN.com. While we have reviewed their content to make sure it complies with our Terms and Conditions, MNN is not responsible for the accuracy of any of their information.