Hi There. Just got 2017 Mazda 3 and I love it but the factory speakers (no Bose) are far from perfect. I want to upgrade to new Infinity speakers but what confuses me most is the tweeter, specifically the crossover part of it. For those of you who know about car audio more than I do just a few questions. If I install 2 way speakers front and rear do I have to upgrade tweeters? If down the road I do decide to upgrade the tweeters anyways do I have to get separate crossovers for them or it is enough to just replace the factory tweeters with new once? Since I am planning to upgrade all speakers to 2 way speakers do I even need the dash mounted tweeters? By reading other posts it looks to me that installing and wiring crossovers it the most painful part of upgrade this is way am leaning towards just 2 way speakers in all doors. Any feedback or comments would be greatly appreciated. Thank you for your attention.