Sure, there was less to them than the modern vehicle but we have fantastic capabilities now that we didn't have then.
"...By now the war was underway in Europe so the rush was on and the Army's tender was quite demanding. Company's bids were to be received by July 22 (just eleven days later). They were given 49 days to submit their first prototype, and 75 days for completion of 70 required test vehicles. The Army's Ordnance Technical Committee specifications were equally demanding: the vehicle would be four-wheel drive, have a crew of three, on a wheelbase of no more than 75 (later 80) inches and tracks no more than 47 inches, a fold-down windshield, 660 lb payload and be powered by an engine capable of 85 ft·lbf (115 N·m) of torque. The most daunting demand however was an empty weight of no more than 1300 lb (590 kg)...."
GM could develop a hybrid chassis/platform to work with various bodies (coupe, sedan, wagon, truck) much like VWs of the past, and have working prototypes in 75 days. Once proven, and with design details published, I believe many would pre-order and get their corporate ship back on the high seas.
Of course they should have done this decades ago, but some shit happened along the way, including the lack of leadership of Clinton, Reagan, and both Bushes, in the matter of efficiency, energy, forward looking technologies.
http://en.wikipedia.org/wiki/File:Covered_Willy%27s_jeep_Wings_Over_Wine_Country_2007.JPG