Pick your partner, fast! The billion-dollar corporate square dance is heating up.

Toyota has made an undisclosed investment in Uber, the ride-hailing market leader, and entered into a strategic partnership to collaborate on new leasing options for drivers, the two companies announced Tuesday.

The pairing is the latest in what is quickly starting to resemble a high-powered corporate dance to determine the future of automotive travel.

Just hours before the Toyota-Uber deal was (somewhat hastily and vaguely) announced, Uber rival Gett and Volkswagen announced a similar arrangement with Volkswagen investing $300 million in the startup.

Lyft, Uber's chief competitor in the U.S., kicked off the trend at the beginning of this year with $500 million from General Motors and plans to develop a fleet of self-driving cars together.

Didi Chuxing, Uber's chief rival in China, received a $1 billion investment from Apple earlier this month — a move that prompted some relationship strains for Uber's CEO Travis Kalanick.

For Uber and its competitors, close relationships with major car companies can further streamline the ceaseless expansion process in key markets by providing access to cars at rates more amenable to drivers.

The car companies, in turn, get a foothold in the fast-growing car-hailing market, which could potentially cut into car sales further down the road. Some, like General Motors (and perhaps Apple), are also using it as a tool to get ahead in the nascent self-driving car market.

Uber's partnership with Toyota is noticeably vague, at least for now.

"Toyota vehicles are among the most popular cars on the Uber platform worldwide and we look forward to collaborating with Toyota in multiple ways going forward, starting with the expansion of our vehicle financing efforts," Emil Michael, Chief Business Officer of Uber, said in a statement.

While Uber was the last of this bunch to secure its big car company backer, the startup has nonetheless raised $9 billion in financing to date — more than all three of these competitors combined — from corporations like Google and Baidu.

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