Yeah the base of the windshield is a high pressure spot on most cars, which is why cowl induction works. But like the video mentioned, you do have to duct it to the engine air intake. If you don't you are just increasing the pressure under the hood, which causes lift. The higher underhood pressure also reduces the pressure delta across the radiator, etc. at the front of the car, which ends up hurting the cooling capability.
My car is missing the rear hood seal, it's on my list of things to replace.