Kia previews RWD sports sedan concept for Frankfurt show

We've driven just about every variant of Kia's Optima sedan and the consensus is that they're all pretty good. We've even gone as far as to call the SX Turbo variant "sporty." However, for the handful of you holding out for a true sports sedan from Kia, the automaker has something even better on the horizon: a rear-wheel driven sports sedan concept that's set to debut in Frankfurt.

The jury's still out on the power train, as the automaker hasn't announced anything beyond the rear-wheel drive configuration and that it's "roaring with energy and ready for take-off," according to Peter Schreyer, Kia Motors chief design officer. We're guessing that the engine room will be filled with something from the automaker's shared parts bin with sister company Hyundai. Will it get the Genesis Coupe's 2.0T or 3.8-liter V-6 or the sedan's new 5.0-liter V-8? We're guessing that, with a body like that, Kia's going big with the V-8.

The concept features a low-slung roof, giving the sedan a coupe-like profile despite the fact that it has four doors and should seat four adults. We see more than a bit of Aston Martin Rapide in both the form factor and the profile. Check out the photos in the gallery and decide for yourself.

We'll be bringing you more information about Kia's sport sedan concept when it debuts alongside the Kia Rio three-door and a visually updated Kia Soul at the 2011 International Motor Show in Frankfurt in September.