I was mildly entertained by this last episode, but I wouldn't say it was one of their best.
The ending I liked a lot though (but didn't like the prophecy of it (and I think the only thing which isn't certain is the timeline)); the cinematography was excellent (as it often is on Top Gear), and it was quite a bold, brave perhaps, way to use air time. That coupled with the BGM (Brian Eno - An Ending (Ascent)) made for a really stirring piece (IMHO); and was great balance to the explosions and silliness of the preceeding few minutes, which demonstrated that Clarkson can be a proper grown-up when he wants to be...
In short, the last five minutes (or however long it was) of the episode made it for me.
Regards,
Rob.