Finding a midrange that is perfectly balanced with the stock components will just take trial and error.
When I upgraded to my Alpine R series separates actually sounded worse until I added more power.
I followed the instructions found in this group, starting with a free trial of Forscan to flatten the eq.
Then I popped off a few pieces of trim and using the instructions here I extended the wires to the trunk where I mounted the new amp in the spare tire well.
I built my enclosure because...
Why do you keep posting this? It is easy to upgrade and nearly everyone that frequents this group has already completed it.
Sorry you think it is such a challenge
you could try it, I don’t see why it wouldn’t work. I abandoned the circuit at the amp and installed my crossover in the door feeding off the 6.5 and supplying to the 3.5 connector to the tweeter.
Went to test drive a 2021 for a kid today and it sounded fine but when put into D with the ac on it idled down to 750 and didn't sound right to me and had a shake. We put it back into park and handed back the key fob. 66k miles and looked overall ok but this didn't seem right.
Opinions?
If you care enough about your sound to find this forum and then take the time post you need a sub.
Listen to all those that made this journey before you. No one who installs a sub says that they would willingly go back to not having it.