There was one after that, Shatner as Kirk for some cellphone company, a landing party is trapped on a planets surface during a meteor shower and they're having trouble calling the ship, red shirts keep getting hit by meteors, it actual pretty good.
I think that's way way way earlier than the directv commercial. Especially since Jimmy Doohan was in it.
That sounds like one of the commercials for the privatisation of the British electrical system (inviting the public to buy shares in a state owned industry which was being sold off to private capital) - Scotty can't get enough power to the transporter, which is why you own a bit of a power company. You can spot that it was British when Kirk says "I don't need a brolly, you wally!' which is not exactly Iowa slang. I think it dates from late 1990 (ISTR that when bombs started to drop during the first Iraq war, the commercial was pulled because of the meteor attacks being reminiscent of bombs - something similar happend to Rowan Atkinson's Bond-spoof credit card commercials at the same time).
I remember when that DirecTV commercial aired. It was kind of sad to see him hawking satellite using Trek.
This is his actual last appearance. www.youtube.com/CkYLENy73wIaPQnJAQB...DhvI2Xtf3G6UsM/0/0/0/video.3gp;interface=wifi