Gummy Bear already did this with his "Gummy
tank" check the "modders" section of the ECF. However, I believe he just stuck a whole steel CE2 through his
tank with filed holes in the sides, you can do the same with the MAP tank. He also made a hole in the side of his tank to re-fill it, he added a screw in the side of the tank to plug the hole back up after filling it like that.
Gummy Bear recommended the following; file the holes instead of drilling, drilling leaves a chance that the drilled plug will drop inside and short out the battery, and you could cut the wires drilling.
The only problem I see with Cartomizers is the filler material getting all messed up with drilling or full of file shavings.