A Homemade Bluetooth Speaker using an extra car speaker?

Okay fellow instructables friends, here's the deal. 

1) I don't really want to pay $50 for a bluetooth speaker. 
2) I ended up with an extra 5 1/4" speaker due to one being dysfunctional out of the box and the company sending me replacements. 
3) I've got a basic background in electronics projects, but am by no means an expert. 

That's the gist of it. I've seen some bluetooth/FM/USB modules on DealExtreme that looked worth getting (around $14), but I'm not so sure of the Audio amplifier circuitry and whatnot. I figure I can figure out an enclosure and whatnot, but does anyone have any expertise/knowledge about the mixer and amplifier stuff? Can they be salvaged from other thrift store finds perchance?

Look forward to the answers! Thanks!

Well, it might be tough for you to develop homemade Bluetooth speaker exactly like original. You need to learn various things before you might start to work. Yes I understand that paying $50 for a Bluetooth speaker is not worth spending, but there are some good options available on http://abcotechbrand.com/browse-new-items shop that comes in the range of $23 to $34. They are loaded with Auto fm functionality and could matchup with your expectation.

No need to buy a Bluetooth speaker system. If you have a stereo with aux input you can get this cheap Bluetooth module. If you don't have a stereo with aux input then buy one that does or at least buy on with a functioning cassette player and use a cassette adapter and plug the Bluetooth module in that way. You have many simple and affordable options here. Then the fun part comes in redesigning the whole thing so it is condenced down into a single portable unit.

http://www.newegg.com/Product/Product.aspx?Item=9S...