The premise asserts that the automotive aftermarket is alive and well, producing great results, and the "audio performance aftermarket" is non-existent. I believe this is a true statement.
I'm going to jump right in and defend the modified classic car vs "supercar" statement. When presented with a premise one can connect the dots in anyway they see fit. That's what's fun about open forums. That being said, my premise was not to suggest that "old cars" can outperform any supercar on all parameters, but merely gave a couple of examples of how they hold their own within a specific performance criteria when "newer thinking" and aftermarket goodies are installed.
To get right down to the nuts and (lug) bolts of it, here are some measurable outcomes:
A "street legal" '69 Camaro was clocked in the 1/4 mile approx 2 football fields ahead of a Bugatti. This was challenged by a participant and I backed it up with the math. 600 feet might have been conservative. By the time the Bugatti reaches the 1/8 mile (1/2 half way) mark, the Camaro is less than one second away from the 1/4 mark and going about 55 miles per hour faster at that point.
Another '69 Camaro hit a top speed of 266 MPH.
Not long ago a vintage car (might have been the above Camaro?) just destroyed any production car in 0-100 and 100-0 times. So, that's a combination of acceleration AND braking.
I don't have good examples of small tracks and tight corners to compare to supercars, so I'll give today's supercars the advantage here.
As the lyrics of the song says: "Two out o three ain't bad". And, if a scoring system were set up for best overall score, some would declare the old cars the winner.
Which takes us to the questions:
Can aftermarket technology make cars make more power and go faster? Yes. Can aftermarket parts increase the dynamic range of an older audio system? Yes.
Can aftermarket parts make cars stop faster? Yes. Can aftermarket parts make our systems sound tighter and more controlled? Yes.
Can aftermarket parts make cars more agile? Yes. Can aftermarket parts make our audio systems more detailed and focused? Yes.
Can aftermarket parts make "the ride" more comfortable, smoothing out bumps in the road and staying flatter in the corners? Yes. Can aftermarket parts reduce strain, harness, and listening fatigue? Yes.
I'm glad to see this little topic is still getting "hits".
By the way, my Rivian R1T accelerates from 0-60 quicker than many exotics at 5x it's price. But, I don't call it a supercar. Or, supertruck for that matter.
Thanks for participating.