Is there such a thing available for an '03 Vanquish, 5.9L v12?
I apologize for the late reply. So far I have never been satisfied with the CD's I have bought on EBay for Vehicle Workshop Manuals. Aston Martin has a Technical website where you can pay a small fee for a 24 hour access to their site where you can download all the information on your particular vehicle. It's url is:
Go there and create an account and you'll be able to see what they are currently charging for this access. The benefit is; there you will be able to download all the information about you Vanquish which will include all the Service Bulletins about your vehicle.
This is what I did for my 2003 Aston Martin DB7 Vantage Volante and have never regretted it.