I spoke with Bose Car Audio on Friday. They said there is no upgrade in wattage available, and further stated that C5 amps put into C4 speakers could cause damage. I told them about your story and that things are working fine for you, but he said they will not retro fit anything like that into a C4 speaker.
I will be sending in all 4 speakers to have a complete change out of components including the speakers and amps this coming week. The only drawback to using Bose is the turn around time which is running 3-4 weeks at present.
