I gave Michael a Carbonizzare after doing the Mission Legal Trouble (I mean, free cars should not be passed down) and put it in his mansions garage when I decided to swap to Trevor for a while.
A while later, I left the mansion to find the Carbonizzare in the street with Jimmy next to it. I checked the garage later, and there was another Carbonizzare that looked exactly like the one i already had.
Later on I swapped to Michael and he had the Carbonizzare next to him, Went home to put it away, and lo and behold the garage was already full with 2 Carbonizzares!
I managed to cram the 3rd one in with the others somehow, but I highly think I am going to have a 4th one next time I check. What in the world is going on with this cloning car?