My Pathfinder has a basic, powerful stereo that is simple, yet yields great sound quality with good stability and endurance.  I built and installed the entire thing myself at a cost of less than $1000(I managed to get some really good deals on a lot of things).
The head unit is an Alpine CDA-7838 in-dash CD player with two RCA outputs.  This deck can be used to control an Alpine CD changer.  I got this from an Ebay auction for $150 used.  It's hooked directly to a Pioneer 12-band EQ because the deck is an older model and didn't come with built-in EQ.  It was given to me by a friend.  The EQ has multiple outputs for front, rear and subwoofer amps.  It's nothing really special, but it serves it's purpose well.  Here's a look at where and how I installed them.
The front door speakers are 6 1/2 inch Cerwin-Vega 2-ways.  I think they're rated at 60 watts each.  They sound great!  I got them from a friend for $80 new.  The rear speakers behind the side panels(no pics) are Jensen 6x9 two-ways.  They're rated at 120 watts each, and I got them from an Ebay auction for $40, brand new,  delivered to my door.
The front and rear full-range speakers are being driven by a Majestic 75x4 watt 4-channel amplifier placed under the front seat.  Sorry about the shady pic.  I got lucky, this amp fits under there without interfering with sliding the seat forward and back!  I picked this up from another friend for $50, used.
Under the hood keeping everything at full current, I have a red-top Optima battery, purchased at a local offroad store for $110.  The 4-guage power cable is by Phoenix Gold, with a 60-amp in-line fuse mounted to the passenger's side inner fender.  The cable runs through a grommet in the firewall to a spot just under the dash where I have a fuse block installed. 
The fuse block splits power to the front amp and back to the Phoenix Gold 1.2 farad capacitor that feeds the sub amp.  I bought the cap from a really broke friend for $40.  It's mounted to the side of one of the sub boxes close to the rear window, right next to the amp.  The hokey-looking bolt I've had to use is the result of a stripped-out terminal.  What were they thinking?  Lead terminal with a fine-thread steel bolt?  Go figure.
Here's a pic of the sub amp.  It's a Legacy LA690 1000 watt 4-channel amp with built in crossover.  Well, it sure is shiny!  I didn't think much of the 1000 watt claim myself, so I took it in and had it tested.  It put out 650 watts with the bass boost halfway up.  Not bad for a $139 amp off an Ebay auction.  I think I have the bass boost all the way up now.  I mounted it against the wall behind the spare tire under the back window, out of sight.
Here's what the back cargo area looks like with only the two Rockford Fosgate 10" Punch XLC's in.  The XLC's are rated at around 150-200 watts and are installed in sealed truck boxes.  They fit great behind the rear seats!  I got them from the same friend that gave me the EQ as a trade for a different amplifier I had long ago.
And here we can see my ported hatchback box with two 12" JL Audio W0's installed.  They're rated at 120-150 watts each, I think.  I threw in this box one day to see how loud it would get.  I got it from a flea market for $120 a long time ago and it was just  sitting around.  Put the all the subs together, and the bass will take your breath away.  I have the amp bridged with two subs per bridged channel for a 1-ohm load.  The top tweeters and mids are disconnected because a Mexican built this box and they are useless to begin with!
One of the other things I have installed in my Pathfinder is a Bulldog remote-starter unit.  It's mounted under the steering column inside the dash with the power feeds coming from the fuse block's input.  Sorry, no pic here, but it's just a bundle of wires, relays, and a black plastic box.  It works great on cold winter days.  My brother got it for me for Christmas, and I couldn't get him to say how much it cost.  I like it a lot, though!  
A little note here:  Remote starters are for automatic, fuel-injected vehicles only.  I've heard stories about people installing one in a manual transmission car and having the car go through a wall bacause the trans was left in gear before the owner pushed the button!  If your car is non-fuel injected, it may not catch and start when the remote unit tries to fire the engine, rendering the unit essentially useless.
Copyright (c) 2001 Aaron Wiltsey
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