This is just totally curiosity.
There's a pretty long history of "toy only" ideas, and I'm not sure if any ever eventually wound up in any books, comics, cartoons, or videogames. Some were better than others, and some were sound ideas with lousy execution. It's actually not too tough to imagine a few Cruisemissiles mixed in with an Imperial air strike on a Rebel base, but this one I'm sure never appeared elsewhere. I've said before, the "figure" is one of the worst of all time, but the idea is a really good one.
The first I can think of is the Troop Transport. I think it was supposed to be a Rebel vehicle, but it may have been Imperial. Very SW-esque design, though it looked rather undersized.
A lot of the old Kenner Mini-Rigs were closer to the feel of Star Wars than later EU ideas. Most of them were quite cool. I don't even have the foggiest idea how many there were altogether.
Hasbro initially gave us some real dung, like Luke's Desert Sport Skiff and Boba Fett's Ridiculous Honkin' Huge Backpack. But Han's Smuggler Pack and the Crowd Control Stormtrooper, as bad as the figures were, could actually fit in somewhere.
We got a second wave of Mini-Rigs (though not called that) with The Phantom Menace. The Gungan Cannon was obviously an aborted Fambaa accessory, but there's also the Gungan Mini-Sub, Mini AAT, and Darth Maul's Whatever Speeder Bike With Lots of Guns.
If you want to be technical, the pack-in mini-vehicles with the Naboo Starship and the upcoming Millennium Falcon fall into this category too.
The only one I can think of is the Imperial Sentinel, which was based on the proposed Clone Guard (?) from the never-produced Kenner continuation of the line in the mid-80s. However, I don't think it really counts, as I'm pretty sure it was based on early designs for the Royal Guard.