I found out that a Japanese Mega CD RAM Cart will work in a US Genesis (https://bit.ly/2UbVLlN) so I ordered one from eBay much cheaper than an original US or a Stone Age Gamer version.
I did have a few questions if anyone may have a similar setup
1. I have a 32x plugged into my Genesis. Does the 32x have the same plastic notches in it the prevent loading a foreign cart like the Genesis does?
2. Can the Mega CD RAM cart be de-cased and either used without the plastic casing or placed into an empty Genesis case?
3. I know a Game Genie can be used to make the Japanese cartridge fit but I don't know if a code needs to be used to make it work. I don't think it does but just asking.
If I get this working as I think it should, the savings for this Japanese RAM cartridge are quite considerable.