Even Elon Musk admitted it was crazy to take on cars. I suppose it's one of those industries that looks simple from the outside because we're so familiar with the user side, but the manufacturing of which is surprisingly complex.
As someone who's worked for one of the big 3, the supply chain and logistics is mind-boggling. Not to mention what it takes to create factories that can put out vehicles at the rate of the big guys. I don't think Google or any other software company could compete without completely retooling their entire company. It's not something you can do as a side project.
To add to this: when GM tried to copy the Toyota model it took them 20 years and they still went bankrupt.... And now Tesla is using the factory that was created for that original purpose.