I'm actually driving a myvi and still new to audio systems. This is how I configure my 4-channel Caliber 2000W amplifier:-

2 channel to my JBL 12" woofer and 1 channel to my front 4" stock speakers. My
rear speakers (don't know the size) is connected directly to my original myvi
headunit.

My problem is sometimes the amp shut down automaticaly and I've got to wait for bout a min for it to switch on back. What's probably gone wrong ? I'm actually in my uni in perak and if possible, I wanna DIY myself.

Another problem is that I'm not sure weather this should be the good configuration for an audio system. Any suggestion that you sifus can recogmend me ? Was actually thinking of changing to a better 4" speakers, is it worth it ? coz sayang wanna drill a hole at my door panel.

Lowered my gain ... So far seems to be alright.

About my configuration , should I disconnect my rear speakers from my headunit ? I've got a feeling that the sound comming out from my front speakers(amplified) and my rear(not amplified) are different and it sounds kinda weird.

btw, wuts the difference between 2ways speakers and 3ways speakers ? Any suggestion on what types of 4 inch speakers should I get for my ride ?

Yea ... I think it got over heated. It usually shut down whenever I switch it on loud for a couple of min and then lower it.

Btw , I'm actually using a pair of stock speakers for my front and my rear. My front are normal 4" component speakers I think , and my rear , I'm not so sure bout it (never open it before). Actually added a 120W pioneer tweeter to the front. Now I'm actually planing to change the front 4" speakers. Any suggestion ?

I might change the tweeters also , don't sound nice to me.

Btw , I also would like to thank you all for sharing with me your experiance

Yea .... its not satisfying actually. But kinda under budget , later got to change my HU and add another amp to power my speakers.