Here’s the kicker: The Polo gets 60 to 70-plus mpg. And it’s really fun to drive. . . . What about the VW Lupo? Not yet. Too small, too compromised. I can’t gush about the Lupo, because it’s really, really small. Sure, it adds about 20 mpg to the Polo’s already impressive numbers, but it feels like a compromise. If I were single? Maybe. But with a wife and two kids? No way. At least not until gas is a whole lot more expensive than it already is. As it sits, a clean-diesel Lupo would be a great choice for the committed environmentalist who’s willing to forgo just about everything for the ultimate in efficiency.

I’m glad VW is going to have a clean-diesel Jetta in 2008. But I won’t buy one. For me, the numbers just don’t work: It’s a $25,000 car that gets 45 mpg. I can buy a Toyota Corolla for $10,000 less and still get 38 mpg—a price difference that would take the Jetta 66 years to overcome, assuming $3 gas/diesel. That’s not to say the Jetta isn’t a great car, and I would much rather drive it than a Corolla. But it just doesn’t make economic sense, and as a writer pulling down a modest income, it’s all about economics.

So to Volkswagen, I offer this plea: Bring the Polo to the U.S. Price it at $18,000. Run an ad campaign that brags about its hybrid-crushing performance at the pumps. And then, sit back and laugh all the way to the bank as hundreds of thousands of Americans, eager for just the right balance between frugal, fun and fantastically practical, mob your showrooms.

Obviously, there’s a lot of room for improvement in the automotive world.