With respect to being an American downloading Top Gear via BitTorrent (which I am), I offer the following rationale.
I do pay for my cable TV service which includes BBC America, which does air Top Gear. Right now, they're airing a mix of seasons 10-12. There is no announcement as to the availability of season 13. As such, I *am* paying for a legal BBC service that does include the show in question. It's just not the current season. Furthermore, we don't get BBC America in HD. The torrent feed is higher quality than what I can get from my Comcast feed.
I will also state, for the record, that if there was a legal way that I could *pay* for Top Gear Season 13, I'd do it, but no such mechanism exists. Not even the iTunes Store has it (they only go up to the end of Season 12).