Watts up doc? Radio amp question

[Kevfra]

:dance: I have the CDR-220 with the factory amp located in front of the battery. Soon I want to add rear speakers, and sooner or later upgrade the head end. I have the silly cup holders stacked above the radio so i can remove both and do a double DIN installtion - once I figure out what to put there. First some questions:

How many watts is the factory amp?
Some amps are linear, meaning they boost whatever you put into them rather than having a fixed wattage output. So if it's a 10x1 you'd get 100 watts out of a 10 watt input. Is this amp linear?

Does it drive only the front speakers?

To add rear speakers will I find rear speaker outputs on the CDR-220, not going through the amp, or will I find rear speaker wires from the amp? Where are they?

Are there micro-pizo tweeters on the dash speakers? Doesn't sound like it. Has anybody found some great micro-pizo units that install on the windshield frame or doors and look factory?

Thanks folks!