A ferrari would be cool, but you know why I don't like the movies?
I grew up on the original 1980's cartoon (every day after school!), and the thing I loved so much about it was the very fact that most of the Transformers in that show WEREN'T flashy or super expensive vehicles. I loved it because I felt like ANY kid, even ME, could pretend that maybe, just maybe, MY family's humble old station wagon just MIGHT BE an Autobot in disguise!!
And in the original cartoon, the humans, Sam and Spike, were normal, everyday, blue collar workers (I remember one episode where a main character was a kid in a wheelchair.) In that show, the Transformers Universe that had a little bit of room for everybody--any kid could pretend something around them might be a Transformer-- and not just the exceedingly tough, good-looking, wealthy, or supposedly important people, which is what the movies are made of. (I realize that's a necessary formula for a blockbuster movie, but it doesn't mean I have to like it.)
I also hate all the stupid, crass,totally uncalled-for humor in the movies, because another thing I loved about the Autobots... was that they always had CLASS, which is something the movies are completely devoid of.
(I will, however, admit to getting a little choked up when Bumblebee told Optimus that he would "lay down his life" for him in this last movie.)
And I totally agree with you over being pretty shocked--and disappointed--when the cop cars all turned out to be bad guys.