Good question. To answer that the rating standard used for these amplifiers would be needed.

Manufacturers have many creative ways to inflate advertised output power. One is the peak music power rating. There is no industry standard for measuring peak music power. Another is RMS power which is more realistic but worthless by itself.

The accepted rating method for car audio is CEA-2006.

but to deliver the rated power using this method the voltage at the amp terminals must be a constant 14.4 V under full load!

Capacitors act as a buffer and supply some reserve current during peak loads but if the terminal voltage does not remain at 14.4V the the rated power will not be obtained.

With all the electronic stuff in cars these days and the pressure on auto manufacturers to control costs do you think the reserve capacity is sufficient to supply another 80+ amps?

I don't think so.