To look at the unique proportions of the Audi R8 -- wedge-shaped nose, short hood, large greenhouse -- it’s easy to forget this all-wheel-drive sports car has been with us since 2007.

Cruise down the street in this mid-engined stunner, and its unmistakable facade looks like a movie prop stolen from a film set.

(Actually the car does have an enviable IMDB resume, showing up in concept form in the 2004 film "I, Robot," and serving as Tony Stark’s ride of choice in the "Iron Man" trilogy.)

But despite being on the market for six years, the various iterations of this car -- V-8, V-10, coupe,  spyder -- have sold only a modest 4,863 copies in the U.S. through April 2013, according to Audi.

This seems low when you consider the R8’s supercar looks and performance come at a relatively affordable price tag. A base R8 V-8 starts at $118,250 with a manual transmission and you have to work hard on the option list to hit the $200,000 mark for a loaded 550-horsepower V-10 model.

So Audi is looking to juice its sales numbers by refreshing the lineup for 2014, tossing in a breathtakingly quick new transmission option and making available an all-new V-10 Plus version.

The result is an even more desirable car that hasn’t even begun to show its age.

Audi wisely kept the exterior upgrades on all 2014 models to a minimum, swapping in revised LED headlights and taillights, updated bumpers and two round exhaust pipes in the rear.

The interior is also much the same, with slightly larger shift paddles on cars with the optional transmission, a thicker steering wheel, and more leather and aluminum trim.

The biggest upgrade is the new optional transmission. Previously, buyers could opt for a single-clutch automated transmission that impressed precisely no one with its speed or smoothness.

But with the 2014 model year, Audi finally made available its dual-clutch S-Tronic transmission as a $9,100 option on the R8. The base six-speed manual is still available on all R8’s, meaning the R8 is one of the rare supercars still available with a DIY transmission. All versions have Audi’s quattro all-wheel-drive system.

We recently logged some seat time in a quartet of R8 models, from a base V-8 coupe with a manual transmission, to the new V-10 Plus coupe. What’s notable about all of these cars is how approachable they are for daily use.

Many supercars treat a comfortable ride or proper visibility as collateral damage for aesthetics and speed. Not the R8. From behind the wheel, it’s easy to forget that you’re piloting a crowd-drawing machine capable of very high speeds.

Let’s take a quick look at each:

R8 V-8 Coupe with manual transmission: $133,900

This car, the darling of the R8 lineup, is the lightest and most nimble of everything offered. Thus, it was right at home in the tight passes in the hills of Malibu.

The mid-engine placement, low center of gravity and all-wheel-drive conspire to give the car a death grip on the road. This lends a sense of near invincibility as you search for this car’s limits; it is very easy to look like a pro behind the wheel of an R8.

Though the optional S-Tronic gearbox is undeniably quicker, this manual is an impressive setup. The clutch and the shifter were also easy to live with, as they were forgiving enough to manage in traffic yet capable of breathy performance under full throttle.

There’s also something resolutely satisfying about the soft metal-on-metal sound as you're hustling the manual shifter around the metal gates.