My youngest son is one year old. One of maybe seven words in his vocabulary is "jeep".
When we are walking out to leave the house he starts chanting "jeep, jeep, jeep". If we get into Mommy's Highlander he cries.
He points out every jeep he sees and has never made an error with pickup, hummer, or FJ.
One of his favorite things to do is stand behind the drivers wheel of my jk.