All Possess/Unpossess events should be done in the game mode!
Interact w/car → Controller unpossess Character → Controller Possess Car → Implement IMC
Exit car → Controller Unpossess Car → Controller Possess Character → Implement IMC
If you do anything to the character when you unpossess you’ll need to revert on possession.
As a last resort for debugging try spawning a new character and possessing it.