I think it's a little premature to state that the car is going to have cooling issues on-track until there is more info. First, those couple of cars were being ran all day by a number of people including a few pro drivers (Pobst and Pilgrim). Who knows if that car had just pitted in and went right back out, or if it was an anomaly with that car or whatever. Historically, GM hasn't had oil cooling issues with the ZR1, and with the dry sump, they have some flexibility to control oil temps. If it's a transmission cooling issue, that's another story. The A6 was not track ready, and would overheat after ~10-minutes. I brought this to light earlier this year, as AFAIK I was one of the first to try and track an A6 car. Subsequent to that, several others had similar problems. Now, LG makes a kit to upgrade the A6 cooling. GM addressed this in the Z06 by increasing the size of the transmission cooler and fan, utilizing a scoop to direct more air into the quarter panel mounted vents, and adding a second transmission cooler at the front of the car. If that doesn't solve it, then it will be an issue that will likely be addressed by LG via a larger and redesigned transmission pan and upgrading the "heat exchangers" used to cool the tranny.
It should be pretty clear the car fucking flies. :29-:30 laps at RA in a bone stock car is hauling the mail (I ran :39's in my '13 GT500 on R6's) and I don't give a shit what tires are on it. And this was the first time these two drivers had them out on-track...so they undoubtedly could go faster.
'17 ACR-E, '14 911 Turbo, '16 Charger Hellcat...a few others...