NFS:Hot Pursuit, the "Biteback" trophy.
That's one where you have to beat a "friends recommendation" (ie, a course that a friend has done quicker than you) in a particular vehicle. Problem is, that vehicle is the top-of-the-range one (ie, last to be unlocked), and I've already done the courses where that car can be used.
So I have to have a friend who has (a) unlocked all the vehicles (b) bettered my time on one of the few courses that car can be used on (AFTER I've already done it), then (c) do it faster than them yet again.
Yes, it's irking me.
(edit: X4, I've just realised you're one of my NFSHP friends anyway