I just installed the Focal system IS TOY 165 for Toyotas. A really good improvement in the bass region, going lower down in frequency also. Better resolution from the treble speakers. Midrange can possibly be a matter of taste, the frequency response is quite different, an improvement to my ears. But YMMV depending on taste.
Very easy to swap out, proper connector adaptors included and everything just slotted in place (apart from one simple issue where I had to remove half a mm of plastic in two small places on the bass speaker's outer rims, easy peasy)