Chrysler's need to find the appropriate replacement for the Dodge Challenger will spawn a family of rear-drive Alfa Romeos. The hottest rumor coming out of January's Detroit auto show is that Chrysler design chief Ralph Gilles is designing a new-age Barracuda to replace the Challenger.

Challenger's two key competitors, the Ford Mustang and Chevrolet Camaro, are both due for major updates in the 2015 model year. Mustang will continue on Ford's last remaining rear-drive car platform, and is widely expected to replace its current live rear axle with an independent rear suspension. Camaro's new Alpha platform is previewed in the Cadillac ATS on sale later this year, and on the Chevy Code 130R concept.

Using the Dodge Charger/Chrysler 300's last-generation platform, the Challenger is by far the largest car in this segment, at 197.7 inches long on a 116.0-inch wheelbase that is 4.2 inches shorter than the Charger's wheelbase. The Challenger is that long because it needed to mimic the 1970-'74 Dodge Challenger's proportions while using the Charger's tall front cowl.

A Barracuda replacement would be much more trim, though still on a RWD platform. Chrysler and Fiat are said to be jointly developing a new platform that's smaller than the current Charger/300's LY. Gilles' Barracuda will be a far less literal interpretation of its namesake, which featured three separate body style designs from 1964 to 1974. They potentially provide a lot of styling cues for the new car, which will avoid a retro look.

"Ralph's always wanted to do a new Barracuda," one well-placed source tells us.

We'd bet on Chrysler badging the Barracuda with the SRT brand name, like the next Viper, rather than using Dodge or resurrecting the Plymouth name.

Another source says the new RWD platform also would serve a lineup of Alfa Romeos, including a sports car, a coupe, and a sport sedan, and would help move that brand into BMW territory.