2010 Kia Soul (© Kia Motors America)

2010 Kia Soul

In the name of sustainability — yours and the planet's — you are determined to ditch that gas-guzzling, pavement-crushing SUV and start driving something more sensible. The trouble is that you still need room for your tuba. The good news is that car designers are devoting more energy to making the interiors of small cars both livable and functional, so you can both cut the cost of everyday driving and get to polka band practice on time and ready to play.

"Today, even smaller automobiles are becoming a living space on wheels," says Larry Erickson, the former chief designer in Ford's Strategic Design Group, who in 2008 became chairman of the Transportation Design Department at the College for Creative Studies in Detroit. "Designers are working to stay in step with trends in entertainment, and the march of technology also drives design. For example, you can push the dash forward to create more room, but then maybe the airbag can't be located properly. But as airbags become less costly and easier to install, we'll see seating that moves people to new locations and makes maximum use of the volume of the vehicle."

Read:  Back Seats

Erickson notes that the American driver has historically associated a small car with a low price, but he says he expects that to change. As the technology (and price) of small cars advances, designers will be able to achieve more interior function.

"In Europe, consumers have been willing to pay for smaller cars with premium features for some time," Erickson says. "As our market shifts to smaller vehicles, I think both advancing technology and a higher transaction price will drive innovation in interior design. New seating manipulation will offer configurations for passengers and storage. New ideas in how we arrange things, the texture of surfaces, the shape of windows, all affect our perception of space within the vehicle."

Given that it takes more than three years to design a new car, Erickson says a wave of technological and design innovation is about to wash over the automobile market. In the meantime, we have a rising tide of small cars with real design character inside and out, shapes that result in enhanced functionality, and fresh ideas on how to make the most of the limited "shadow" of a compact platform. Here are the 10 subcompacts you can buy today that meet all the above criteria, and they cost under — or just a little more than — $20,000. Though these small wonders won't haul the entire brass band, each can carry at least one big horn.

Honda Fit

Click to enlarge picture2009 Honda Fit Sport 5-Spd AT (© American Honda Motor Co., Inc.)

2009 Honda Fit Sport 5-Spd AT

Cargo space (seats up/down): 20.4/57.3 cubic feet
Base price: $14,900

Though long of roof, the second-generation Fit doesn't fall into the "box-on-wheels" category of some other cars in this group. Inside, the Honda's rear Magic Seat can be folded down, without removing the headrests, to create an expansive, flat rear cargo area. Or fold the rear seat bottom cushions up together or by the 70/30 split, and you have a floor-to-ceiling cargo area that can be accessed through the back doors, while the cargo space behind the seats remains intact. Rear-seat room is outstanding, while only the tallest drivers may wish for more legroom. Ten cupholders, eight storage slots, two concealed cubbies and a large glove box hold the small stuff.

Bing: Honda Fit

Hyundai Elantra Touring

Click to enlarge picture2009 Hyundai Elantra Touring (© Hyundai Motor America)

2009 Hyundai Elantra Touring

Cargo space (seats up/down): 24.3/65.3 cubic feet
Base price: $15,995

Originally designed for the European market, this compact wagon offers the seating comfort of a midsize sedan and the cargo space of an SUV. Materials are not upscale, but the interior is well-made and easy to live with. Headroom and legroom are outstanding front and rear, and the seats are supportive. The glove box has an air conditioning vent that can be opened to cool a few drink cans, and there's covered storage on top of the dash. The Elantra Touring leads this group in cargo space behind the seat, and features in-floor compartments. Fold down the seats, open the wide rear hatch and this little wagon could swallow a bedroom set.

Read: Safety Ratings for the 2010 Hyundai Elantra Touring

Kia Soul

Cargo space (seats up/down): 23.7/53.4 cubic feet
Base price: $13,300

The Soul puts a little more emphasis on passenger comfort and style (check the optional glow-in-the-dark seat upholstery and red dash cover) than on cargo capacity. There's plenty of legroom and headroom for even long-legged teens in both the front and back seats, which are well-designed and comfortable. Drink holders and storage cubbies abound, and include a compartment in the upper dash and a glove box with a shelf to help keep it organized. The rear cargo space is vertical, although there's a nice organizer under the floor. The 60/40 rear seats fold down — but not quite flat — and the small size of the rear hatch will make it difficult to load larger objects.

Compare: Kia Soul vs. Pontiac Vibe vs. Toyota Matrix

Mazda3 5-Door

Click to enlarge picture2010 Mazda Mazda3 (© Mazda North American Operations)

2010 Mazda Mazda3

Cargo space (seats up/down): 17.0/42.8 cubic feet
Base price: $20,290

This Mazda's interior will appeal to buyers who wants to feel as if they spent more money. Softer plastics and brushed-metal trim, nice fabrics, leather on the wheel, and especially the soft blue "greeting" illumination when you open the door at night all contribute to an environment that's almost — but not quite — German. But style gets you only so far. The Mazda3 is short on creative storage compartments. Legroom and headroom in the back seat are lacking. Even the glove box is small. The rear cargo area is a good-size and covered with a rigid shelf, but there's no stowage under the floor. The 60/40 back seats fold almost flat to create a space that's useful but not extraordinary.

Read: User Reviews of the 2010 Mazda Mazda3

MINI Cooper Clubman

Click to enlarge picture2010 MINI Cooper Clubman (© Perry Stern)

2010 MINI Cooper Clubman

Cargo space (seats up/down): 9.2/32.8 cubic feet
Base price: $21,150

Ten inches longer and an inch taller than the standard MINI Cooper, the Clubman aims to bring a little practicality to a vehicle that exists mostly to be cute and fun to drive. The added space all lies behind the colorful front bucket seats. The rear seat has 2.4 more inches of legroom, which makes it a "possible" proposition for adults, but that's all. Entry is eased by a "club door" on the right side. The rear seats fold flat to create creditable space for a car this small, and there's hidden storage under the floor. You can open one or both of the split rear barn doors, but then they are in the way and, unlike a hatchback, don't offer any rain protection.

Watch Video: See the MINI Beachcomber Concept