Ok, but the tweeter has an in-line capacitor. Thats pretty much the same thing, only obviously not as good because the woofer is still pumping out the full range.
Im sure they must be other cheap, so called component speakers, that use the same sort of setup? Ive as set of co-ax speakers in the rear of my car that have a crossover box, so the crossover itself surely cant determine what makes a set of speakers a component set.
Getting back to the original post, I think it would be fairly pointless spending out money for a proper set of speakers and then not amping them. If I remember correctly, the standard HU in a billabong gives out 20 wpc or something? Only by having the factory 40wpc sound upgrade would it almost be worth doing. I believe when you have that upgrade, they fit the same stereo / speakers as youd get in the standard 172.