https://www.youtube.com/watch?v=jLUf6KwosOQ
At about 1:30 in the video they have an on board camera.
This guy is just cooking up that hill and it's all high speed stuff.
And here is another hill climb run with an on board camera. https://www.youtube.com/watch?v=d9Lopg7YbUY
This is a short run (sprint), but very impressive driving. You'll notice when the guy finishes and gets out of the car he is breathing hard. He didn't breath all the way up that run! Happens to the best of us.
Check out these little purpose built hill climb cars. https://www.youtube.com/watch?v=IwM5SAJJpn0
They look like a Honda Pilot, but crazy fast (4 cylinder bike engines) and man do they handle. Towards the end off the video you'll see them going around a fast off camber corner and they just simply stick. And when the driver gets one out of sorts they just come back.
Update: Those cars are not purpose built hill climb cars. They are KartCross cars. Kartcross is a big deal in France and I guess other European countries as well. Like autox, but done on the dirt and I guess asphalt tracks as well. I have the names of a couple of manufacturers and will do a little research.