They would be wired parallel to the midranges, with a high pass filter in line with them to protect them from low frequencies. You simply tap the wires to the midranges. I put a pair of these in my rear doors:
https://www.amazon.com/JBL-GTO19T-Pr...s%2C189&sr=8-3
They come with high pass filters and various mounting brackets. You could easily add them to the stock mounting position on the doors. An identical version is sold as the Infinity REF-275tx.