I was going to start a 'If you could change one thing' thread, but this pretty much covers the same thing.
My biggest bone of contention is with the SatNav, the new one (can't remember what it's called off the top of my head).
There's no quick way, or at least none that I'm aware of, of shutting it up if you want to keep listening to the radio. I find it a pain in the @rse and it goes absolutely sp@stic at you if you deviate from the route, for example by pulling in to motorway services.
Also, I wish you could cancel the low screen wash warning. It's quite distracting when you're driving along, keeps on flashing up.
Martin