Minecarts and boats have no ability to hold active effects. This can be easily seen by throwing a splash potion of invisibility at a boat/minecart. This would make sense for survival, but it is a detriment to mapmakers. Most of all, the inability to make minecarts/boats invisible.
Here's a command to demonstrate.
/summon Boat ~ ~1 ~ {ActiveEffects:[

]}
You can change "Boat" to "Bat" to see that the syntax is correct.