D was a General Motors franchisee. D received an invitation to bid on approximately 1200 school bus chassis from Ps. D consulted with the GMC Truck Division and General Motors Corporation (GM) regarding prices and availability. D proposed to supply several different sizes of chassis at specified prices. The chassis were described as “Chevrolet” brand in the bid but were to be manufactured by GM Truck. D's bid was accepted. The initial deadline for orders was set at 31 July 1990. All orders submitted prior to this date were properly filled. On 26 July 1990, the EPA enacted Federal Emissions Standards changes for heavy-duty diesel engines, thereby rendering the 8.2N diesel engine described in D's bid out of compliance with the regulations effective 1 January 1991. In mid-July 1990, GM tendered an extension of time for ordering chassis from 31 July to 31 August 1990. D conveyed this option to Ps, which accepted the extension. GM then requested the cut-off date for orders be moved forward to 14 August. Ps agreed, and orders were transmitted to Bobby Murray between 1 August 1990 and 14 August 1990. On 10 August 1990, P received a message from GM setting the final chassis buildout date at the week of 10 December 1990, but warning that estimated production dates could be pushed back due to a potential shortage of the requisite brand of automatic transmission. On 24 August 1990, GM then stated that due to “the uncertainty of major component availability,” no further orders for school bus chassis would be accepted. On 30 November 1990, GM told D that any orders placed between 1 August and 14 August 1990 would not be filled due to unavailability of Allison automatic transmissions. The Allison transmissions would not be provided until February or March 1991, but installation of the 8.2N diesel engines would be illegal in consequence of the modified EPA regulations. On 11 December 1990, D notified Ps the chassis could not be supplied. Ps bought from another source and indicated they would hold P liable for any excess in cost. Ps sued D for a total of $150,152.94, representing the difference between the bid prices and the actual amounts expended by Ps in purchasing similar chassis. D claimed, inter alia, that GM breached its contract with D to provide the chassis at issue and that D had merely been acting as an agent of GM. Ps and GM filed motions for summary judgment. Summary judgment was entered against D and in favor of Ps. GM's motion for summary judgment was denied. D contends its lack of performance should be excused pursuant to 2-615.