AUBURN HILLS, MI – Chrysler Group is preparing for the worst as it readies the ramp-up of its redesigned-for-’08 minivans. And that’s not all bad.

Production has yet to begin, and the auto maker already fears it may have underestimated demand for the vehicles’ breakthrough Swivel ’n Go seating system.

“Unfortunately, we are the worst,” marketing chief George Murphy says of the auto maker’s ability to predict consumer response. “We miscalled the Wrangler hardtop 4-door. We’re nervous about the (Sebring) convertible now. This is another one.”

Demand for the Jeep Wrangler Unlimited’s optional “Freedom Top” removable roof has been so strong that Chrysler had to call on its supplier for more deliveries. The supplier, Michigan-based Meridian Automotive Systems, is adding manufacturing capacity to fill the increased orders.

Meanwhile, the Sebring convertible – which comes in three styles, including a retractable hardtop – launched to sales of more than 1,400 units in April, its first month of availability.

Murphy, senior vice president-marketing, declines to reveal projected take-rate volumes, but admits the auto maker is on edge.

“We’ve got a number for Swivel ’n Go, and we’re all a little bit nervous because we’ve been light (in the past),” he says here during a media preview of Chrysler’s new advertising campaign in which the new seating system is featured.

Chastened by its experience with Wrangler Unlimited, Chrysler has alerted Swivel ’n Go supplier Intier Automotive Inc. that additional production may be necessary.

Swivel ’n Go, which debuts this fall with the production launch of the Chrysler Town & Country and Dodge Grand Caravan, allows second-row passengers to face the rear of the vehicle by turning their seats 180 degrees. Also available is an optional table that can be set up between the two rows for activities, such as dining or game-playing.

Deployment of the seats and table are allowed while the vehicle is moving because Chrysler has proved to regulators they are safe.

Against this backdrop, Stow ’n Go is a wild card, a Chrysler spokesman suggests.

Also from Intier, Stow ’n Go, which conceals second-row seating beneath a minivan’s floor, thereby increasing cargo capacity, still will be available. So the auto maker also must calculate how many vehicles are likely to require this system instead of Swivel ’n Go.

Murphy recalls how, after Stow ’n Go made its debut in’05, Chrysler forecast a 15% take rate for standard fold-and-tumble seating.

“It went to zero so fast you couldn’t believe it,” he says. “When you have a feature that really resonates, it’s going to be a pretty high take-rate.”

Stow ’n Go, which debuted in ’05, is widely credited with boosting Chrysler minivan sales. T&C deliveries rose 42% compared with 2004.

Unlike the redesigned Wrangler, which is in short supply according to dealers, Murphy assures there will be no shortage of the auto maker’s new minivans once production begins this summer.

“Minivan is such a high-volume vehicle that, trust me, there will be more than one in every dealership (at launch),” Murphy says. “You won’t hear a dealer saying they don’t have a minivan.”

The vehicle will be assembled at a pair of Chrysler plants – St. Louis and Windsor, ON, Canada.

Sales of the T&C and Dodge Caravan minivans were down last year, 12% and 6.9%, respectively. But Chrysler and Dodge minivans dominated the segment, claiming a 4.3% combined share of the total light-truck market, according to Ward’s data.

The Honda Odyssey followed with a 2% share after enjoying a 2.1% sales hike vs. prior-year. But its unit sales total of 177,919 still trailed the first-place Caravan’s 211,140 deliveries.

emayne@wardsauto.com