already a topic on this http://www.tfw2005.com/boards/transformers-toy-discussion/184820-girl-who-loved-powerglide.html
No. We're all making it up and you caught us out in our devious lies. Any pictures of the "heart" you may find are clever photoshops also created to deceive you.
We've known about this for many months, and Draven posted close-up pictures back in the middle of June, and we've still got two new threads running about it now. It's definitely fun to find features you didn't know about, though. After all, that's the nature of these guys.... MTMTE, and all that.
Ow indeed, doesn't bear thinking about, but there's probably a specialised site dedicated to this sort of thing somewhere.
Pretty interesting how they put that in there... Especially since it was one episode only, but hey, it these kind of hidden homages that make looking around the figure fun.
Astrotrain definitely requires Astroglide for the 'fourth mode'. Sort of like how the tin man kept needing all that oil in Wizard of Oz. He had a heart on by the end of the movie, too.