what I want to know is why they tested a convertible model in the snow... 

Now why would you do a traction test in the snow and turn traction control off?  What was the point of that exactly?  I'm sure the 4.2 would beat it's bigger 5.2 brother also.

Well that's Toyota's over aggressive nanny tronics to prevent old and blind people stepping on the gas pedal when trying to brake.     TC is supposed to find the optimal level of grip based on slip to prevent exactly what happened to that 4S which no doubt is heavily biased to the rear mechanically. 


Did your old Lexus have a mechanical diff or was it perhaps trying to e-diff it?

Well that's Toyota's over aggressive nanny tronics to prevent old and blind people stepping on the gas pedal when trying to brake.     TC is supposed to find the optimal level of grip based on slip to prevent exactly what happened to that 4S which no doubt is heavily biased to the rear mechanically. 


Did your old Lexus have a mechanical diff or was it perhaps trying to e-diff it?

No I'm not talking about throttle and brake overlap. The T/C itself was doing the braking. Snow under tires, hit the throttle, they spin, T/C brings the hammer down, you go nowhere. It was utterly useless. Switch it off, let the tires spin and the car will eventually free itself. This was a 1996 car so the T/C system was pretty crude and their was no stability control, but some cars at least still act this way on loose surfaces like snow or gravel, I've seen it happen. 

BRZ for the win!