I kind of scratch my head when I see this and it's not the first time, so you're not the only person who feels this way. Human eye and brain can't distinguish speed increases after roughly 130-150mph. It is not entirely inaccurate in GT6. You don't really get a sense of 'speed' in real life, unless you start looking at your surroundings. That's usually a combination of the realization that 1)things are going by much quicker suddenly, but the kickers are NVH and getting pushed into or away from your seat back.
If your focused and tunneled in on the cars ahead/behind and the track, you're not going to notice much other than the feelings of accel and decel. Any g-forces/loads for that matter. Just something that I've noticed. In couldn't tell you any difference in perspective between 180mph and 140mph. It can't be distinguish. It's like...'overload - sensory cannot compute!'. Even track edges and paint don't really give off a sense of speed in real life at a point. The only things I find that give off some sort of sense of speed are lines in roads. Some track edges and boundaries are broken lines or dashes, rather than solid and those things blur into each other. But on straight up pavement, you would have a tough time guessing after 130-140 or so. Trees should just be a blur in your peripherals. If you look to the side at them in gt6, it hurts to attempt to focus on what you're going by. In fact, it's impossible. Same thing in real life.
I definitely notice a lack of speed in chase view. Everything actually feels like it is going on slower, even though it isn't in real time. That's why I tip my hats to people using that view. It makes me feel stupified, like I'm behind the 8 ball.
I am not shocked that stiggy is so f'ing fast...I AM shocked that he uses the chase cam AND is so f'ing fast. Pretty sure he uses a wheel too, which makes it that much more impressive.
I don't like the interior view, because you can't shut the wheel and arms off on the screen. You can't even change the lock of the drivers arms to at least match your own and your wheel rotation. That's all I used to use, but I found it impractical recently. To me, that is. I like the bumper cam, because it may as well be my eye perspective in the car, considering my rig positioning...I see my own arms, wheel and column mount...so feels just like racing from the perspective in my kart. I actually thought about making a rig out of a chassis I don't use much anymore haha