What I did for master IA-8
First corner (the 1st tunnel one): brake between 300m and 200m, drop from 4th gear to 2nd gear, and go through the tunnel in 2nd gear staying close to the inside of the corner.
The "S" (left corner followed by right corner where those annoying little pins are): do them in 2nd gear and stay over the racing line. Once out of the "S", do not pressure yourself into up shifting asap or will loose speed. Go out of the corner, let the 2nd build up a little bit and then up shift to 3rd gear. Then let the 3rd gear build and right when you reach the bridge, up shift to 4th gear.
The final 2 corners (slight left corner before entering the last tunnel and right corner inside last tunnel): always 4th gear, loosen the throttle a bit when entering the first corner so not loose control over the rear, then throttle to the second corner and once again release throttle to go through second corner. Try to stay over 185km/h while going through this corner even if the car slides a bit as you go out of the corner.
The Lamborghini countach '74 is a wild horse, a very tail happy car, it will try to spin in almost every corner. Dont push it too hard or it will spin.
The gold really tight, it will take you a lot tries. If you see the demo ghost getting far away from you, just pause and try again.
The gold is 0.38:2xx, at start I was doing like 0.38:8xx and 0.39. But at the end I was consistently doing 0.38:500, 0.38:400 and 0.38:300 until one try everything when right and it gold.
Be persistent, dont give up.