I don't know for certain whether the TSB is time / model year boxed or not. It shouldn't make any difference really - showing them you know a bit about the history will make them realise they can't fob you off. This is the reason it is worth ringing other dealers nearby and asking to speak to the service manager to see if he recognises the problem and has done the work before. Don't mention the age of the car, ask whether they are aware of the issue. Once they admit it, then tell them you're bringing your car in for them to look at, and can one of their technicians (that has done the work before) come out with you for 5 mins while you show him. That's what I did, when I got back they booked the car in for the following week to have the work done