[honk]

The possibility of a vehicle fire is real.

The place I once worked lost a brand new Ford truck this way. It literally burned to the ground. The truck was pulling a trailer over Pacheco Pass in Gilroy, CA on a hot day. The fire investigator hired to examine for cause determined that the fire resulted from the expansion of overheated transmission fluid having puked from the fill pipe and being ignited by the exhaust system. Since the truck had received a first servicing only two days before it was concluded that the trans. must have been overfilled because of the incorrect procedure used to check the level bringing the mechanic to add fluid where none was needed.

So, it is not advisable to overfill automatic transmissions, and particularly ill advised in vehicles equipped with catalystic converters because they are often hot enough to ignite oil.

The oil's capacity to expand is why most if not all level checking protocols instruct that the level be checked either hot or cold as specified on the dipstick, usually.