Stereo systems? Especially P-ups?

Hi guys,
I'm getting to the point where I am starting to think about stereo systems and I'm curious what others have done with theirs. Im especially curious about head units or bluetooth units, amps and speaker locations. I know sound deadening will be a massive undertaking.
Pics would be great.
Thanks,

Speakers low in the door is fairly easy. The door is big enough to make a great speaker box. Be sure to put a plastic cup over the top side of the speaker in case rain comes in around the window.

Or you could put just about any speaker box in the area behind the seats.

I built an overhead console with the head unit. Cables can run down the windshield pillar.

I attached the power amplifier to the side of the under-dash air vent.

I haven't done mine yet, but I'm planning to go overhead as well with the head unit. Maybe tweeters A the top of the pillars and woofers in the doors.

I'm thinking out options right now too.  I really don't want to have a head unit mounted in the dash and the majority of music that I listen to is thru my phone.  I'm gonna go with a Bluetooth amp hidden under the dash and just plug in speakers.  Here is a pic of one on Amazon, not sure if I'll get this exact one but you'll get the idea