not directly at the throat, you will have the lowest pressure at the point where the profile in the sidepods is closest to the ground. (highest air velocity)
You will need to see the pressure profil under and above the car (body) where the pressure difference is greatest, you will have the point with the highest downforce.
The pressure difference varies along the car.
You have your CoP (centre of pressure) along the longitunal axis.
This is similar in pricnciple to your CoG (centre of gravity) for the different masses along the longitunal axis.
You normaly aim to have your CoG and CoP close togther, to minimize balance changes with speed.
in this example you would have the point at app. the cockpit.
venturi tunnel exit on an Lotus 79
pressure distibution in tunnels (Indycar)