Frankfurt Auto ShowFRANKFURT – In this modular era in which suppliers ship fully assembled axles, corner modules and instrument panels direct to the vehicle plant, it is surprising the industry has not figured out a way to supply a fully assembled sliding door for a minivan.

For instance, inner panels for traditionally hinged doors for sedans or pickup trucks frequently are supplied as modules, complete with the window regulators, locks, motors, audio speakers and the necessary wiring already installed.

Brose inner door panel comes fully assembled with window regulator and other hardware attached.

The vehicle assembly workers need only install the inner module, then finish off the door by mounting the interior trim panel with all the switchgear, armrest and map pocket.

For most minivan programs today, however, the internal components of power sliding doors are shipped piecemeal to the OEM assembly line, including the lock, latch, speaker, power supply and anti-pinch mechanism.

The OEM line workers then install the hardware as they assemble the sliding doors.

The Brose Group, a German supplier that has been producing window regulators since 1928 and helped pioneer the modular hinged door a decade ago, displayed at the recent auto show here a power sliding minivan door that can be delivered as a module to the vehicle assembly plant.

The module consists of an aluminum inner panel containing the necessary hardware and can be delivered in-sequence, says Markus Schultz, Brose’s director-advanced development for door systems.

A sealing bead is applied around the perimeter of the inner door panel to minimize noise and vibration, and the module also can accommodate power window regulators, Schultz says.

Sliding doors are becoming increasingly complex, and some now offer power lift windows. Since the dawn of the U.S. minivan in the mid 1980s, sliding doors had only fixed windows that could not be raised or lowered.

Today, the Honda Odyssey and Toyota Sienna minivans offer power second-row windows as standard equipment.

Minivans may not comprise the hottest U.S. vehicle segment, as some former customers are migrating to cross/utility vehicles and SUVs, but Brose is not deterred.

“CUVs will continue to take market share away from minivans, but demand for sliding doors should remain stable,” says Jan Kowal, president of Brose North America.

For instance, the new Mazda5, a unique 6-passenger cross between a small minivan and a CUV, has two sliding rear doors, and both have power windows as standard equipment.

If these multipurpose vehicles gain popularity in North America, and should more minivans continue to offer power windows, Kowal figures the inner door module could gain acceptance.

Brose is working on a few development programs with OEMs for the modular sliding door, Kowal says. There are cost advantages, but Kowal declines to give specifics.

“No customer will do this without a cost advantage,” Kowal says.

Competitors who also offer power sliding doors and liftgates include Delphi Corp., Intier Automotive, Aisin Seiki Co. Ltd. and Nippon Cable Systems Inc. (Hi-Lex).

Brose expects to finish 2005 with sales of €2.1 billion ($2.5 billion), an increase of 7% over last year.

The company has ambitious growth plans to reach €3 billion ($3.6 billion) in sales within five years, with 75% of the business in doors and 25% in seat adjusters.

In the past two years, Brose has set up six new locations, including a North American headquarters and engineering center in Auburn Hills, MI.

Four of the new facilities are for door-system assembly in Chicago; Tuscaloosa, AL; and Sindelfingen and Rastatt, Germany. The sixth plant produces seat adjusters and latches in Ostrava, Czech Republic.

Brose is slated to open four more plants within the next year in London, Ont., Canada; Holzgerlingen, Germany; Gothenburg, Sweden; and Changchun, China.