2004 coupe
23K miles
original stock exhaust
new (~200 miles) Bridgestone Potenza Pole Position S-04 tires
radio and AC/fan off, windows up
Soundmeter app, phone held between my head and steering wheel.

newly paved asphalt highway @60 mph on flat surface (constant accelerator position) = 62 dB
idle, stationary (neutral or in drive) = 43 dB
engine off = 22 dB
ambient, outside, night (crickets, locusts, tree frogs) = 35 dB
while accelerating briskly or on rougher roads I did get occasional readings over 70.

for comparison, engine off my daily driver (04 Olds Alero) is 23 dB. will try to see where it is at 60 mph.
my wife's voice, after I forgot to take out the recycling = 92 dB.