Bridging A Headunit with Dual Voice Coil Speakers?

Hi I have a Kenwood Deck with a 5 channel amp. My amp is powering my door speakers and subs at 40 RMS to the door speakers. Now I know this is probably not doable because I dont have a deep enough understanding of bridging but as far as I am aware a bridgeable channel is one that can handle 1-2 ohm loads. The reason this is not doable with your head unit is that it cant handle 1-2 ohm loads only 4.

But what If I bridged the rear and front channels with a dual voice coil speaker? This way I could keep the ohms at 4 ohms.

I ask this because I would love to add 2 more speakers to my setup on my dashboard. Now of course I could just wire up my Headunit and run the normal 22 rms setup and this would be the easiest way to hook up a few speakers with the only cost being the speakers themselves. But my amp pushes my doors at 40 rms and it would be cool if I could get the extra power from the HU to match my amp settings. I dont want 4 speakers on my dash (that is a but much) so I will have my 2 rear channels just taking up space/power for no reason. Might as well use that unused power if I can right?

If this doesn't work id like to know why or be directed to a place that can teach me why it wouldn't. Thank you!