Stereo & Electronics - Installing a system in my 02 Z28

So I have a new head unit, sub, and amp that need to be installed. I'm kind of a new to car audio stuff so I'm trying to decide between doing it myself or getting it done professionally.
Basically I want to know how I should connect the sub and amp to the new head unit.

The sail pannel subs are blown out and barely work so how should I go about disconnectiong those? Should I disconnect them from the amp?

I appreciate the help guys, I've been hitting up this forum ever since I got my car a month ago and just decided to join.

Replace the sail panel speakers. You want to disconnect the hatch speakers when adding a sub, not the sail panel speakers.

What sub/amp combo did you go with?

The sail panel speakers are subs though in the monsoon aren't they?
Why would I want to replace them with weak subs when I'll have two 12"s in the trunk?

The sail panel speakers are subs though in the monsoon aren't they?
Why would I want to replace them with weak subs when I'll have two 12"s in the trunk?

Yes, they are subs.

Replace them because they are blown. If they were good I would say leave 'em. I haven't replaced mine since they're still good and I have 2 10's.

I don't understand why they are needed though. They would only put out weak bass which would be drowned out by the larger subs.
Seems like a big waste of money and I'm on a tight budget.

when you replace them, since you are putting in a seperate sub, you need to replace tehm with a 2 or 3 way type speaker. for your rear fill. not with a midbass driver.

For now I'll just have to live with the hatch speakers and my door speakers.
Eventually I'll have the whole car rewired for new speakers.
But good bass is all I need to be happy for now.

My setup has changed though I decided not to use the two 12"s but instead get one good 12" in a little box.
My plan is to put it right behind the back seat facing up and slightly angled back facing the hatch.
Does this seem like a good idea or a bad idea? Is there any reason I wouldn't want to do this?

i wouldn't see an issue with it. in fact, with only using the hatch speakers in the back, it's probably better that way. it'll be a bit more balanced with 1 12, rather than 2. just a question of what you're going for. boomy, loud bass, tight controlled bass, sound quality, or.. i jsut want others to hear me. haha!

Really I'm looking for a combo. I like a lot of bass but I like quality where I can still hear the rest of the music.
For now I'm leaving all my other speakers stock until I can afford to rewire the car.

Another question I have is what will I need to install the sub amp and head unit, as in adapters and mounting and stuff?