I loved Vikes comment " . . . and the opening it creates for slower-witted but better funded rivals to steal their thunder" which immediately brought to mind GM's attempt to steal Mazda's thunder with their version of the rotary engine. Google GMRCE for the details on how that worked out. Better funded but slower witted indeed
What GM missed out on was a rotary 'Vette (I believe it was supposed to be a 4-rotor powerplant compared to the 2-rotor unit slated for the uber-Vega), but in a cruel twist of fate, the biggest loser on the GMRCE project was really AMC. Never exactly awash with R&D dollars, they blew an unaffordably large share of them on a vehicle designed around the high-output, compact rotary that GM had agreed to sell them. When the engine was canceled, AMC was faced with a tough choice - write off the project or try to salvage it. With AMC's typical "can't afford but can do" spirit, their engineers hacked up the firewall, creating a huge bulge into the passenger cabin in order to wedge an i6 under the low hoodline that topped the tiny Wankel-sized engine compartment.
And yeah, that was the Pacer. The exterior was entirely AMC's fault, but the bizarre front cabin space with its screwed-up footwells - you can thank GM's fickleness for that. Problem is, the i6 still didn't have the output of the rotary, so the wide, greenhouse-heavy Pacer could barely lumber along. Eventually, AMC bit the bullet and effectively destroyed the lines of the car's front end (such as they were) by bulging up the hood to accommodate the small-block V8 needed to drive the little monster. The cumulative effect of all the band-aids and baling wire created a horror unmatched in the annals of American automotive styling - at least up to that point. Apparently offended that AMC had managed to be all-time #1 in anything, GM would later greedily seize the "ugliest ever American thing on wheels" title for itself with the awe-inspiring Pontiac Aztek (the mere memory of which was as good a reason for killing off Pontiac as anything else I can think of).