According to Yahoo! Finance, which obtained an excerpt from Elon Musk: Tesla, SpaceX, and the Quest for a Fantastic Future, Musk and Page had gotten as far as agreeing on a price, an expansion plan and a guarantee that the company wouldn't be broken up. What's more, the agreement stated that Tesla's founder would be allowed to run the automaker for eight years after Google took over.
But then, things changed. After teetering on the edge of bankruptcy (and taking some rather desperate measures to prevent the plunge), Tesla reported $11 million in quarterly earnings – its first such positive report – on the back of $562 million in revenue. Its share price nearly quintupled to over $200 a share, and the company paid off the nearly half a billion dollars in loans it'd taken from the Department of Energy. Negotiations promptly fell apart.
Yahoo! Finance has the whole story, direct from Elon Musk: Tesla, SpaceX, and the Quest for a Fantastic Future. Head over and give it a read.