Up for sale is a Alpine in-line 4x45 car amplifier. I installed this into my WRX to help the stock head unit add a bit more juice to the speakers. It worked very well and because of it's size, the install was quick and easy and it fit behind the dash without any problems. This amp wires directly into your factory harness and therefore you don't have to run power from your battery to it. It will work with any car and has hi-level and low-level inputs.
I have the original box and all of the adaptors to make it low-level hooking it up with RCAs in addition to the hi-level I was running with a factory head unit.
I had it installed for about 6 months but recently (yesterday) had a full system installed professionally and took this out.
The price on amazon fluctuates between 101-120 on a regular basis so let's call this one $80 shipped to your door.