Not sure why this is becoming a track issue.
I've raced at Kyalami in a road car.
Will not race my road car on the track for many reasons.
Track cars have better more rigid chassis, sway bars, strut braces for a reason, a normal chassis will bend, even a E92 chassis will bend.
The brakes and suspension is not rated for track use.
Your bushes, control arm, engine mountings, none of these have been rated for track use. your engine cannot withstand the temperatures of track days.
The oil in your car is not rated for the temperatures experienced on the track it will jump to 120 degrees quite easily.
Your road car will suffer after 10 laps and will never be the same.
And last and most important, your insurance does not cover it.
So sorry to dull the glamour of track times, it's fun & maybe an indication of handling, but really, road cars should not be used on the track. This is not top gear.
Track times and road cars is hardly relevant, to me anyway.
Most people never take their road cars on the track and understandably so.
The cars are meant for road use and designed for road applications.
Tnx bye.