i'll be quick, as i want to get to bed
the initial charge of the cap is taken from the battery, this is a good thing, once you start hitting bass and draining power from the cap, this has to recharge. where does the charge come from? yep, the battery, which should be using as much of it's output to power the amp. by fitting a cap and using it, you will be removing voltage from the amp, to charge the cap, therefore defeating the object of fitting one in the 1st place
too many people believe the max power review pages, it says it all when total car audio no longer recommend using them
best thing to do is upgrade the big 3, see a far bigger improvement doing so, than fitting a cap