It has like a little lever behind the head of the driver's seat, I don't know what it does.
I think it's just a poorly secured headrest, Gatillo. They had to change it from the one on the 15 dollar BARC Speeder since that one had an elongated peg that stuck out to securely fasten into the BARC Trooper's backpack; I think that, like the waist joint on the Jet Pack Clone, Hasbro didn't make the fit of the new headrest secure enough.
As for the exploding thing, mine doesn't explode at all (which I actually like, considering that if I even look at the POTF2/Vintage speeder bikes they blow apart) and it doesn't even come apart very easily. Overall though, for 10 bucks, it's worth picking up, but it's definitely not of the quality we're used to for Speeder Bikes at this price range.
And on the film accuracy tip, has anyone tried to put Stass Allie on a regular ROTJ/CW speeder bike yet? How does she fit?