Dont know if there has been much talk lately of where Clarkson, May, and Hammond will land, but it sounds like Netflix. The show may already have a new name, House of Cars.
http://www.engadget.com/2015/05/13/netflix-top-gear-house-of-cars/
fka Top Gear - The Grand Tour Thread
http://www.engadget.com/2015/05/13/netflix-top-gear-house-of-cars/