To the trained ear, these issues might sound like the normal hubbub of manufacturing engineering - where completed designs are translated from drawings and data into smooth assembly work. But in Project America, the suppliers' involvement helped shaped the design.
For example, it was not just a matter of adjusting the Endeavor's cockpit dimensions to accommodate its heating and air conditioning module.
It was a matter of simultaneously designing a heating and cooling system that met the Endeavor's needs as well as those of the Eclipse, Spyder and Galant - and then modifying the designs of all four models to accommodate the system.
Door hinges proved to be a disproportionately tricky issue.
Although the average consumer won't think twice about the Endeavor's door hinges, the Mitsubishi team gave them the attention worthy of a lunar landing.
The placement of the front-door hinges affects critical structural issues.
The hinges go on the A-pillar, which helps determine the lines of the pillar. The pillar itself plays a key role in crash testing and structural integrity.
And once the A-pillar design was set in stone, it would be fixed for all models in the platform.
"What really constitutes the platform is the floor that's under the front seats," Sims says. "All that structure where the A-pillars tie in. Once that front door is set up, it's difficult to move it. That was probably one of our biggest challenges going through the platform line.
"There are advantages and disadvantages to the way we're doing things. One disadvantage is that some components get locked into position in ways that you could never foresee, so you have to work around it. But I think when you see the results, you won't be able to tell that we had a struggle there."
Another difficult decision rested on the dimensions of the frame components that hold the model's engine and radiator.
Each of the Project America models will carry a V-6 engine, but there also will be a dimensionally smaller four-cylinder engine in some models.
Vehicle interior components were another sticking point. For the SUV, Sims' team wanted a roomy floor console big enough to contain a laptop computer or a woman's large purse. That had a design and spacing impact on the coupe and sedan.
The instrument panel also required extra work to make sure it would align with the doors of different models.
"You have doors that move, and they have to line up and close precisely with millimeter tolerances every time," Sims says. "That becomes a manufacturing issue, too - making sure there's no variation in alignment during the manufacturing."
And because robots will install the instrument panels, designers had to consider how the devices would reach into each model and make sure the interior designs did not obstruct the installation.