2x2x2 is the basic sund setup. With the aftermarket HU, you will lose the tweeters in the doors. Not much of a loss IMO.
If you prefer, you can hardwire. However, there are also adapters out there. Regardless, you will need to use an antenna adapter.
<span style='color:gray'><span style='font-family:Courier'>1995 e36 3 Series RIP
1999 e46 3 Series BURN IN HELL
2000 MR-S Roadster= Current</span></span>