I got stuck here, too, but was able the next day to ace it on the first try.
Now I can do 360s all day. It's just one of those things. Here is my take
on it:
It is important to note that you have to rotate in the right direction
(indicated by the giant yellow arrows) and have to 'keep your speed up' for
the game to recognize your 360.
I head for the cones in 3rd, downshifting to 2nd and revving the heck out of
the car when I get to the cones. You can also get a running start at the
cones from either side to get up more speed. I enter towards the left
pointing towards the middle (of the cones) if I am going to be spinning
clockwise.
Crank the wheel all the way to the right and hit the parking brake. When you
are halfway through, release the parking brake and turn full opposite lock,
flooring the throttle. That's all there is to it.
You can try and envision your front wheels always trying to point where you
came from, in other words, when you are at 180 degrees, your front wheels
should be in the middle of turning the other way from where you turned them
first. By the time you finish the 2nd 180, your wheels are straight again.
It may also help you to envision that the 360 happens first by your back end
rotating around the front, then halfway through, the front starts to rotate
around the back.
Try driving around elsewhere in that infield pad and practicing the 360s
without the pressure of the cones being there. ONce you get the hang of it,
go through the cones. Make sure you learn this, because a little later they
will have you go through and do a 360, then around a cone and back through
doing another 360 in the other direction before coming to a rest where you
started.
It seems like once you do it, it suddenly makes sense and is easy to do. I
think I was trying too hard to hit timings just right or something and that
screwed me up. It was my first sloppy try the next day that worked, because
I wasn't concentrating very hard.
happy spinning,
~daxe