Running Power Cable + front speaker sizes (2010- Doblo) ?

[Ryan della Doblo]

Hello, I am looking to install a simple 2.1 component and subwoofer system into my fiat doblo (mpv) (2010) and am struggling to find a location through which I could send a supply to the amplifier without ripping the car to bits. The amplifier will be in the boot along with the subwoofer by the way.

Also does anybody know the size of the front component speakers and if there are any issues with space behind them for fitting larger units ?