You are correct. I remember when my son found a Rover (driven by Thompson & Thompson) in one of the TinTin books. "Look dad, they have your car!" However, there are no really good names in the whole lot. Captain Haddock? Professor Calculus?
On the other hand I was inspired by "Popeye" and my green 88 is named "Olyve." It comes in handy when my otherwise perfect wife complains of the stain in the driveway. "Why honey, that's just Olyve oil." (insert Popeye laugh here).
"Swea'pea" would be a good name for a green Rover, although "Swea'pea oil" doesn't have as good of a ring to it.