So a lot of people don't know that The Royal Tenenbaums originally ended with Sloop, and in fact there were some early screenings of this version of the film. Eventually it was replaced in favor of a vastly inferior song. Four years ago I did a mock up of the BB version, which I'm finally uploading to youtube now. I was using fairly primitive video editing software and a fossil of a computer, so it's a bit rough. Still works great as a closing song, I think.
https://www.youtube.com/watch?v=7u6ZN-r8eqUThere was another version that used the Beatles "I'm Looking Through You" (Anthology version). I made my own version of this one too, I'll have to try and dig it up.
That doesn't surprise me. I'm pretty sure Wes Anderson is a fan of the Beach Boys, and more than just a casual one. I was just watching Fantastic Mr. Fox this morning, the Criterion Collection edition, with his commentary on, and he mentions Heroes and Villains when it plays early on in the film, and how the film has a Beach Boys motif. I was so caught up in it that I was late for work.
P.S. By the way, I like it.