about to install a pioneer av1c-d3 into my s3 which has factory nav plus fitted .ineed to know best double din facia to use i have heard the a4 one is closest.and is there a power connection adaptor for wiring head unit.and is it a canbus system.not worried about speaker connections as will be using genesis five channel amp focal speakers and junking the bose sounds which i rate about minus 10

any helpwill be much appreciated