if anyone wants a great amp for a totally stealth install, the arc mini 125.2 makes for a very good candidate. i just made an intermediate bracket that adapts the mini to the oem amp mounts. it clears the hinge/spring mechanism and the trim panel if you install it just right. i made copper pins to jack into the stock harness so no wires have been cut.

it is powering sws8 underseat subs. i have mbquart qm100's with qtc19 tweeters on all 4 corners powered by the HU. the system sounds very good. its not the best sounding system i've ever done, but is MUCH better than the stock setup. its not very loud so i'm also planning a 4ch arc mini for the mids/highs. i just haven't decided yet how to get the inputs for the amp. i may cheap out and use the speaker level inputs, or may go the mobridge/bit one route.

Great find! Perhaps a line out converter for your amp sound signal?

thanks to bruce_miranda i found out that the signals from the HU to the subamp are already line level so no need for a converter. i hooked up a scope to them just to be sure, since i doubted that they were in fact line level. looks like the peak voltage is about 3v. if i use the 4ch arc mini for the 4 corners i'll just its speaker level inputs if i go the cheap route.