Right. I admit it. I'm out of ideas. WHERE ARE THE MMMC ROBOTS?
Right. This is driving me nuts. I KNOW the place to unlock those two MMMC robots is around here somewhere. I'm pretty sure it's not through endless playing of the game types, as I'm well past level 1000 now and I don't think anyone would be so evil as to bury them that deep. Which leaves Story Mode. I've played the thing again and again, right up to that GODDAMNED Balloon Racing bit and I've not found them. I give up. You guys have successfully managed to hide something from me...
*sigh*
Back we go... at least it's keeping me busy.
I get the feeling that it's jupiter.
When you go there, the cutscene is one of the MCC robots walking on, saying "MWHAHAHAHAHA" and then walking off.
Unfortunately this means you have to beat the ridiculous Jera Balloon race again (Curse you extreme bug!)
I can't find them on jupiter! Where are they??!?!? 
I got the robots so long ago I don't really remember on which planets I got them.
Let's just say they are on a planet after you have finished the maya story. You have to win in order to get the robot.
*yay* planet trawling 
[edit] 
i got them both: with maya, win saturn & uranus twice
EXCELLENT.
Never before has a videogame secret eluded me for so long. I was about to resort to using the cheat, fer god's sakes...
win saturn & uranus twice
Twice ? Didn't remember that… :?
a lot of the easter eggs and in-jokes are shown when you play the same planet twice (rather than moving on to another planet to progress the plot). When you get the robots though, there's another hidden easter egg in the script 
Cool! Think I'm going to hit the story mode again!
Gotta love the whole "Earth kid pressing the button" scene.
Don't remember that. It it something I forgot or is it an easter egg you can uncover after completing the Maya story?
BCM. Uranus. Keep visiting.
I still don't have the MMC robots, but I can't say that I've tried this yet. I've been trying to get them forever, and finally I know how 
Thanks
hmm... I managed to unlock the MM-2 at Uranus, but I can't unlock the MM-1
I beat Balloon Racing at Jupiter twice, and I'm out of ideas.
lol, thanks for the hint Fedule!
let's just say that going back to certain planets again, even though you've completed them for part of a story, can sometimes be rewarding