donor platforms, Chrysler also allowed consideration of rear-wheel drive. Ultimately, the L-body was ruled out, as it was considered too light-duty for either the size of the vehicle or its planned six-cylinder engine. During 1978, Chrysler began research across the United States, seeking what features customers desired in a potential minivan, finding agreement in its planned goals. Though potential customers found concept sketches "ugly", Chrysler still found a potential market of nearly 1 million vehicles per year, with Chrysler selling 215,000 of them. In 1978, both Lee Iacocca and Hal Sperlich were fired from Ford Motor Company, moving to similar positions within Chrysler Corporation. The same year, Chrysler Corporation merged the truck engineering division of Dodge within its car counterpart of Chrysler. By 1979, Chrysler chose front-wheel drive for the minivan project, codenamed "T-115". Though the van would share its transverse engine and transmission with the K-cars, it would be based on a separate body structure. Approved by Lee Iaccoca at the end of 1979, the T-115 project would cost $500 million to produce, funded as part of the $1.5 billion in federal loan guarantees given to Chrysler. From its 1979 approval to its 1984 launch, the proposed T-115 design would undergo several major changes. Originally intended to use four sedan-style doors (similar to a station wagon), Chrysler changed to two sliding doors for the rear, claiming better parking-lot access. The configuration was ultimately changed to a single sliding door, as Chrysler wanted to market the van to commercial buyers. While engineers wanted to make a left-side sliding door an option, its deletion was done to reduce production costs. During development, the configuration of the rear door was also contentious; initially favoring a tailgate, designers shifted to a liftgate (a design also used by the K-Car wagons). On the exterior, the side windows were redesigned to become flush with the body in 1981; while requiring a major redesign of components and tooling, the design change allowed for a reduction of wind noise and drag. To further reduce costs, a number of visible interior components were shared with the Dodge Aries/Plymouth Reliant, including the instrument panel, interior controls, radio, and various trim items. Drivetrain choices proved problematic as the 2.2L I4 of the K-cars was considered inadequate; the 3.7L Slant Six was unsuited for transverse mounting. The Mitsubishi-sourced 2.6L I4 was adopted as an interim engine until the Chrysler V6 engine