Upgrading my audio!

[SoundofLife]

I drive a 2015 Toyota Corolla LE. Right now, I have everything stock except my sub and its amplifier. I have 2 12's Rockford's P2D4s powered by their prime amp that shoots 500x1 @ 2 ohms. The birth sheet says 619, so that's 309.5 to each sub when the two of them can take 400 RMS. With my back seat down, and my windows down a little, i get a small effect that i love. It's the massage effect, also it some how improves the sound. Now, I want to multiply that lovely feeling by like 10. So I have been having a problem with deciding, do I want to go to T1D412s at 800 RMS or T1D415s at 1000 RMS. If I do the former, I'll get a 1500 watt amp, i'm sure the birth sheet will show the RMS at around 1620 RMS. If I do the latter though, I thought of having 2 1000 watt amps. I've been told that's better than getting one 2000 watt amp. Anyways, what say you on that notion?

FYI: I do plan on getting T1675s in my doors and T1693s powered by 300x4 rockford amp. What would your car audio priority be in this situation? Improve highs and mids first, or shoot for the upgrade (and final change of subwoofers). Thank you! Also, I do have an aftermarket, but it's in the closet for now.

[ShadeTreeMechanic]

You need a ton of power to do what you are talking about. Even 3kw won't get you ten times the output. To get twice as loud (3db) you need to either double the power or double the cone area. You just missed all kinds of black Friday deals.