It seems that while the brand is of course different, the generic WW2-originating term "jeep" still exists in the GTA world. The police radio in SA would also refer to some vehicles as "jeeps" as in the generic category (like "sedan" or "SUV").
Throughout V I noticed that both Michael, Trevor and Dave Norton mention the army driving "Army Jeeps"
I found it odd considering that they should have said Army Canis' to keep it canon
That's funny, I never noticed that before. It makes sense though, considering the history of the jeep and how the word "jeep" itself was a nickname given to it by soldiers. Is it trademarked in that sense or is it open season?