2 amps is much higher than normal drain on a battery as it should be of the order of a few millamps. First of all, I would not trust the in-car ammeter. Disconnect one side of the battery and install a decent multimeter selected to current mode, in series between the battery terminal and the disconnected lead to verify the actual discharge.
As you have already removed all fuses, I support Richards suggestion that it could be down to some aftermarket device, maybe an alarm of some sort? 2 amps equates to 24 watts which would be enough to emit smoke, heat or smell if it was down to broken insulation somewhere!
