This was my windsurf/SUP wagon in 2008.
It fit my 9'8 SUP, 2 paddles, 3 windsurf boards, 4 sails, 2 masts, 2 booms, a surfboard, tent, 20L fuel and water bottles, 1 t-shirt, 2 shorts and crusty jocks
This is my 11-2 in my Land Rover Defender doesn't fit but a 10-2 does all the seats lay flat. Great 4WD if you love hitting the beach
I get a 10"2 in a Skoda superb with around 1 foot to spare- insane. Would be confident a 11" would fit in with a board cover .