I bought a 2008 XK recently, got a few niggles but am really enjoying it.

I have noticed though that whenever the electronic parking brake is released (whether by pressing the parking brake button or just by setting off), almost exactly one second later, there's a (fairly quiet) "click" audible from the back of the car. Is this normal? What could it be? Should I be concerned? If I take it to a garage, what should I be asking them to look at?

 

It seems like a normal sound. Either the actuator, caliper, or cables are just disengaging.

I wouldn't worry about it until the the whole thing stops working (like mine!)