I'm not sure if that study is fair.

After all, is there a comparative analysis in regards to the quantity of vehicles?
More cars of certain type will certainly lead to more tickets.

Also, Hummer's are almost always personal vehicles while the Escalade, Yukon, etc. are often used for taxi, limo, etc.

Most taxi, limo drivers keep their speeds down because of tickets cause driving is their work. Hummer etc, is not real a "livery" vehicle.

__________________
----------------------------------------------------------

"When two people agree on everything, one of them is not necessary" - Arliss