Tried out this nice little recipe - not sure the results are that fast, but the car is a lot of fun

Take one British chassis, and lighten to a little over
21002300lbs. Stir in 4 big fat slick tyres.
Then add in a big American V8 and add parts to reach a PI of
S700. Omit any thoughts of downforce - there ain't any to be had.
And the result is that an old friend makes it's return.

Loved this car in FM2, but when I first built it out in FM3 I had trouble driving it

But, eventually I remember the old maxim - you don't drive a Cobra, the Cobra drives you. So I stopped pushing it for more speed and let it run at a pace the car was happy with. And the old girl came to life. Not fantastic in the fast corners which didn't help at the 'Ring, and not a great top end - even on the Benchmark Ring it only just hit 200mph. But it has great acceleration up to about 170mph, and has that controllable oversteer I loved in FM2. The 'Ring may not have been any great shakes, but around Kaido and Positano this car is immense fun.
So, the times - might as well get S Class started.
N: 115.816; 112.546; 133.367; 134.334
K: 124.358; 162.462; 114.314; 111.194
P: 98.265; 77.527; 97.865; 114.364
I think that gives me totals of 496.063 for the 'Ring, 512.328 for Kaido and 388.021 for Positano.
Incidentally, I'm another one who can't believe you ran this for close on 4 hours straight

I'm on of those who has just tried to get a clean run and, unless it is noticeably bad (i.e. original Range Rover run at Positano D) have left it at that.
Another pointer to how nice to drive the Cobra is, for the first time I managed a complete run of all 4 stages of a course without incurring any penalties and having to restart (Positano).