Bridge two channels, or power four?

I have a four channel Alpine MRV-F340 amp, that puts out about 55 wrms to four channels. It can be bridged, so that it puts out 90wrms to two channels. My question is, should I bridge the front two channels to get more power to the fronts, and run the rears off the deck since they are just fill anyway, or should I hook up all four channels? What would you guys do?2004 BMW 325ci.

Alpine CDA-9885

JL 300/4 and 250/1

JL XR 5.25 comps

Infinity Kappa Perfect 12

By the way, I'm running kappa two-ways all the way around....100wrms rated.2004 BMW 325ci.

Alpine CDA-9885

JL 300/4 and 250/1

JL XR 5.25 comps

Infinity Kappa Perfect 12