I have JL Audio XR 6.5inch 3-way components, no rear speakers.
The woofers in the doors stock location and mid and tweeter in fiberglass kickpanels. Mine a sedan also. You could start with the amp from your headunit if it has one then upgrade to a separate amp when ready.
No, no, there is no climate change, it just getting hotter and hotter....and hotter. Yeah, right!?!!?