Ok, just got gold. Changed my LCD TV display mode from "normal" to "game". It increased the gamma so everything was a little brighter.
You must catch the F40 at or before the right turn at the end of the straight. The sooner you pass him, the better chance you have of getting gold but if you aren't around him entering that tight turn after the straight you have no chance of catching the leader. The rest of your lap will just be practice (or you can start over).
After that, which I call the half-way point, you need to memorize the track based on left turns because each one is slightly different and you can't take your eyes off the road. The first left has a left kink followed by a hard left. The reflectors are deceiving so be sure to brake after you pass the kink. The second left is an immediate hard left after a right kink so brake as soon as you see the reflectors and enter slow to prevent wheelspin. The third left is another kink+hard left but this time it is uphill. Like before, don't be fooled by the reflectors, wait until you get to the kink to brake. Keep wheelspin to a minimum and power out using the entire track. You have some run off this time but make your way to the left side of the track for the next part. Then there are two esses. The first is rather tight, brake for the entry then power through in a straight line at half-throttle until you can see the exit. The second is a little more open. I flubbed it a little with some wheelspin but still caught the leader just as I was crossing the line. Overall, keeping wheelspin to a minimum will make you faster. The Lambo likes to drift, but it loses tons of speed if all 4 wheels break traction. Keep the drifting to a minimum and focus on corner exit speed and you'll catch the leader.
My video...