I wasn't bullshitting, It is true that Vigilante missions are not available to this game's Hunter, and it does count as cheating, if you do find a way to use it for them. 
 
hey man sorry i didnt mean that you were bullshitting i was talking about the guy who said that he completed vigilante missions in the hunter 
 
That's ok, I had a feeling you were talking to raymond, because he was bleathering rubbish. 
I still do think that despite it's habit of flipping over, The Rhino is by far the quickest and most reliable, I got up to Level 402 in at least  or 4 hours with it. 
The police car and FBI cars are not always good, the doors eventually get knocked off and that means on-foot cops will find it easier to arrest you, and the Enforcer (Swat Van) is too slow. 
I found that going really fast with the tank, is what was causing it to flip when it hit stuff, so I avoided hitting too many other cars and kept it's speed at a pace.