In Micromouse (https://en.wikipedia.org/wiki/Micromouse) - a competition where autonomous devices solve a mouse maze - the fastest competitors are all using fans to increase traction (and thus speed).
However, a small caveat that might be worth considering is that while the suction indeed increases speed, it might be more accurate to say that it primarily improves acceleration instead of car speed: The issue often lies with achieving rapid acceleration rather than with maintaining high speed. Even systems with relatively low traction can reach high speeds given enough time and distance, but the ability to accelerate quickly is crucial in competitions like Micromouse.
https://en.m.wikipedia.org/wiki/Brabham_BT46
An issue with aero features (other than not producing their effects at low speed) is their ability to stall. Ground effect was especially dangerous (back when high-ground-effect designs were allowed) because if it stalls during a high speed corner (say from driving over a bump, like a kerb maybe) you can instantaneously lose a huge amount of downforce, which is obviously quite dangerous.
But if you want to increase the acceleration you need traction, your tyres need to be glued to the asphalt. Since you don't have aerodynamic pressure at those speeds you need to suck the vehicle to the ground.
Length = Point2 - Point1
Length * Time^-1 = Velocity or Speed
Length * Time^-2 = Acceleration
Length * Time^-3 = Jerk
Length * Time^-4 = Snap or Jounce
Length * Time^-5 = Crackle
Length * Time^-6 = Pop
Fourth, fifth, and sixth derivatives of position: https://en.wikipedia.org/wiki/Fourth,_fifth,_and_sixth_deriv...
So people will say that something which accelerates quickly is 'fast'. Or they will say, when they feel themselves initially being pressed back into their seat as a plane starts its takeoff roll, that they are experiencing 'acceleration' when what they are experiencing is actually jerk.
The thing is, you can't actually feel motion at a constant speed - so the only thing that tells you you are acquiring speed is your body's experience of acceleration - so when you feel yourself accelerating, you associate that with speed. Likewise, your body also can't really tell the difference between constant acceleration and just... being at a different angle, and maybe a bit heavier than normal. So it's when you experience changes in the apparent direction of 'down' and the overall 'weight' you're feeling that you think 'oh, we're accelerating'.
My favorite way to get a sense of what acceleration, jerk and snap feel like is to focus on what happens when you're in a car that's braking hard. You're decelerating at a relatively constant rate while the brakes are applied - it feels as if 'down' is pointing slightly forward, meaning you'd be sliding off the seat if it weren't for your seatbelt holding you back. When the car finally stops though, there's a very abrupt change in acceleration - a 'jerk'. 'Down' switches to pointing straight down again, very quickly. You're pulled back into your seat. That's jerk. And specifically the sudden onset of that swing in what direction 'down' is pointing, and then its rapid disappearance is snap. Your body feels like it's being 'jerked' around when the car stops precisely because that motion has high snap - you experience a sudden high amount of jerk, then the jerk ends.
In a vacuum. If you roll the window down, or if the atmosphere starts ablating you into a hot plasma then you may realize you're going very fast.
By definition they are not experiencing any acceleration.
If they are experiencing a drag force they are also experiencing a thrust force that is equal to it because they are traveling at a constant speed.
‘Feeling the effect of a force’ is not the same thing as ‘experiencing an acceleration’.
So it’s changes in acceleration that create movement sensations, not acceleration itself.
If you flip from one to the other suddenly, your brain figures out ‘we’re rotating’ pretty quickly though.