Jim,
It's something i have talked about with a few tiger owners. My car runs a Ford Motorsports 302 340hp crate engine, Fluidyne alloy radiator (no shroud), 6 blade flex fan and horn block offs. It has CAT headers ceramic coated. The car runs cool and for reasons not known to me.. never seems to radiate heat into the passenger compartment.. even the firewall is quite cool.
There is heaps of heat that comes from the front wheel arches and when you pull up at lights you feel it waft out up the outside of the door.. but inside the heat doesn't seem to come in.. and its not running any thermal shielding under the carpet.. just normal jute felt.... i am confused by it.