can comp/mids be wired parallel like subs

Currently I have 6.5" components in my front doors and 6.5" mids (no tweets) in my back doors of my Mazda hatchback.  Both the front and rear are 4 ohm speakers and have a RMS around 120 watts.  They are currently being pushed by a 4-channel amp at 40x4 in 4 ohms.  I didn't go with tweets in the rear because I was told it just needed "filler sound" in the rear.

My question is what are my options to get more power without the obvious "get a bigger amp"?

I had thought about replacing my 2-way crossover with a 3-way crossover, attach my rear mids to the 3-way crossover, and bridge my amp to 100x2 in 4 ohms.  I was talked out of this option though because I was told it would probably create an awkward sound presentation.

Another option I was thinking of, I don't even know if it can be done, which is why I wanted to ask all of you experts.  The 6.5" woofer in the front component set is the same 6.5" woofer that is in the back.  Can those two woofers be wired together in parallel, dropping the ohms to 2 and allowing me to bridge my amp to 2-channels?  Would my amp be able to run bridged at 2 ohms or does it have to stay at 4 ohms?  How would the crossover come into play with all of this?

Will any of these things work?  Are there other options or should I just get a bigger and/or second amp?

Thanks for your help.

If your amp is 2ohm stereo stable and drivers are crossed at different frequencies, why not?

I'm no audiophile, but I have read over and over about "beaming". This is probably what they were talking about when they said it would sound "awkward".

give more info on your amp and the frequencies of the crossovers and I'm sure the experts will be glad to explain in greater detail.

Agree with ianarian.  Sometimes you have to experiment for yourself to realize what's best.

What you are overlooking is the fact that the biggest difference between subwoofers and woofers that play higher frequencies is...the frequencies!  Where we might run our sub freqs at a 2 ohm load on the amplifier and not tell if there is a difference in quality, we cannot do the same with frequencies higher than subsonic.  With reasonably accurate gear, mids powered by an amp at 2 ohms will not sound as good as they would if the amp were loaded at 4 ohms.  That is why you don't see such a practice as commonplace.

And, you are trying to "match" power to rating.  Realize first that ratings of each are not entirely accurate, and second that you are using only 1 watt or a portion thereof in normal listening.

Other than that, any drivers can be paralleled or series-wired just as subwoofers can be.  When you connect speakers, you are loading an amplifier with an impedance;  if you don't overload it with an impedance that is too low, it will still work.