The suspension on most of these cars is also far from normal. There's very few cars in the world which make an8 second pass on independent rear suspension. Most of these cars have straight axles and 4 link suspension.

I really want to see a Tesla Roadster make an 8 second pass with whatever tires it needs because tires alone won't get you there. They got some serious engineering in that thing to make it hit 8 seconds with a suspension that doesn't make you hate life.

  x = 0.5*a*t^2 = 0.5 * 41.25 ft/s2 * (8s)^2 = 1320 ft = 1/4 mi

  v = a*t = 41.25 ft/s2 * 8s = 330 ft/s = 225 mph

This is why you see so many approx 2.9s 0-60 times in higher end sports cars, it's hard for aerodynamics to affect it much over the first couple of seconds.

But for the first couple of seconds, you can't generate much downforce from aerodynamics because you aren't going fast enough. And there are limits to what a spoiler, etc. can generate. For a lot of street legal sports cars, this all evens out about the same way, and they end up with very similar 0-60 times.

If you try and systematically knock down all of these problems, you'll end up with a top fuel car. In that case you may get ~1000lb of downforce from exhaust alone, which gets you past the first bit while you are going too slow for the big wing to be really effective.

Now that the 2015+ Mustang has IRS, I expect to see more of them as well. I think there's already one in the 8's.

But yeah, IRS is a major pain at that power level. Most (all?) of the performance cars today have IRS, so I expect improvements to come.