It is a 4 channel 65 watt amplifier unit, directly connected to the ISO connectors for it's power, input and speaker output. No need to connect it directly to the battery as it's power consumption is very low. Should be able to connect it in 15 minutes. It is so small it can be placed under the seat.
I've read a lot of feedback from enthousiastic German users on forums and it has been rated "sehr empfehlenswert" from Autohifi magazin.
Anybody here experience with it?

https://www.i-sotec.com/de/products/ampl ... amp-4.html
Following two articles are unfortunately in German but give a very good idea how it is installed (in a VW

https://www.autohifi-magazin.de/sixcms/m ... .22727.pdf
https://www.autohifi-magazin.de/sixcms/m ... indung.pdf
Blaupunkt will also introduce a similar amplifier around august/september this year:
https://www.blaupunkt.com/uk/7607792130_main.asp