Hypothetically, of course, and without regard to applicable laws, one looking for the full episode watchable somewhere other than a Youtube mailslot might find oneself blundering around some theoretical BitTorrent search site (that of course I have no personal knowledge of) for what I've seen referred to as season 12 episode 2, some claim this can be found with a search for TopGear S12E02. I've also heard that that the road (and mall, and assault landing) test of the new Euro Focus, a particular piece of video that those who have seen it claim is a must-see, can be found in episode 6. Once again, no personal knowledge of course.
If one prefers to check the official TopGear site and twiddle their thumbs for a good long time waiting for the Beeb to make it available in a form you can buy, they're at
http://www.bbc.co.uk/topgear/