Without question, the GT by Citroën Concept Car.
Thought it was the most badass looking thing. "It's gotta be good!" I said. What a disappointment. Looks nice in photos at least.
Apart from the engine braking (lack thereof), I wasn't disappointed in this uniquely whacky car, though I admit I don't whip out the Concept much compared to the other two (both of which I like).
Highest torque figure in the game - what's not to love?
Oh, right. Not being able to hold out the XJR-9 in the Dream Car Championship because the battery ran dry....
In other news, I ♥ the Ferrari 2007. The 2010 does suffer in comparison. I also bought a second Muira to mod up yesterday, right after an Audi R10 (which I admit is likely rubbish, but I had stupid amounts of money to spend). Ooh, 20 more million? Again? Thanks, Bruce*!
For either GT40 Race car (both 69' and modern LM gulf livery), try dropping the LSD Accel below 10 for sanity. Plus, the Chapparal 2D can pound the snot out of the AI at Monaco, and look and feel great doing it.
I don't think I've been overly outraged at any particular vehicle, because I typically knew what I was getting going in (too much research). Never felt the love or found much use for the Panoz, Lister, or XJR-9 yet, but bought them anyway. They look cool, but I haven't found their niche; I had some hope for the Lister.
The Ford XR8 rocks.
*aka Bob.