OK, no offense to anyone, but the comparison commonly tossed around here about MC being as common as OotG is total nonsense and I've heard a half dozen people repeat it.
OofG came out a lot earlier, around the same time as Air Zonk. They were both part of the "new software lineup" advertised through Turbo Zone (NOT TZD) and Totally Turbo in 1992. They're both copyrighted 1992. The Turbo was still a semi-viable system that year - there were no clearance sales, and Toy's R Us had not yet begun trimming down their selection.
By 1993, Turbo games were much harder to find, making it safe to say that games like MC had nowhere near the distribution of earlier releases even if just as many were pressed.
Let's look at the slate of Turbochips scheduled in the 1993 Club Duo Catalog:
Jan - Darkwing Duck (makes sense, the copyright on the actual Turbochip is 1992)
Feb - Hero Tonma, World Sports Comp
March - Bomberman '93
July - Magical Chase
August - Bonk 3 (makes sense because this is the only game released with the updated box design)
Oct - Battle Load Runner (oops, what do you know, never released)
The accuracy of this list is supported by the Bonk 3 box design, the copyrights on the games, and the fact that BLR wasn't released. So, I'm going to argue that MC was the second-to-last Turbochip ever released and is therefore pretty frickin' rare.