I replaced my not so "powerful" 6 speaker system with polk components up front, rockford 2 ways in the rear doors, Kicker CompRT 10" shallow-mount sub and a kicker 5 channel amp. The sub & amp combo fit perfectly in the center trunk storage box thing hah so you can't see anything.
It sounds great now, I do wish I went with Focal upfront and will probably swap later on down the line. I'm no audiophile and didn't want to spend 20k lol, but its night and day difference now compared to the "powerful" 6 speaker system that it came with.