No ideally you need proper 2 way components up front, and most people go with 5.25" as you'll need adapter rings anyway. Try the 230slx deluxe. No point wasting Rainbows in the rear, just some cheaper 6.5" coxials will do as the flimsy doorcard they are screwed to will put paid to any bass you might be hoping to get from them.
If you want decent sounds in the A3 you need to install a sub, doesn't matter what you fit in the cabin.