I just replaced my terrible door speakers! They sound awesome and 20 times better than stock. I even bought cheap *** Jenson 6 1/2's and they seriously sound so much better than stock. $25 for the pair and I'm super happy. Highly recommend replacing your door speakers even if they are with somewhat cheap aftermarket speakers. You will love the difference and the install is a piece of cake.

 

The only difficulty is if you go with speakers deep enough that the standard 1" plastic spacers won't let the magnet clear the door. I found I needed 1 3/8" to clear but then the speaker gasket was too close to the rear of the plastic door trip hole. I cut a bit of the door trip away and then had to make a custom made spacer out of two layers of plywood to offset the speaker forward in each door about 5/8" of an inch.

The front speakers in the Bose system almost suck as bad as the subwoofer but add so much more to the sound.

 

I used Metra 1" spacers for my mids (kappas) and it wasnt much of a problem. Cutting out the plastic piece to mount the tweeters was a pain, but looks nice in the end result.

 

The cheapo speakers that I installed cleared fine and fit perfect. I cut out the crappy built in speakers from the surround frame and then cleaned up the sharp edges and used some self tapping screws to attach the new speakers to the spacer. They fit perfectly and even have (haha) adjustable center tweeters. So once they were installed I aimed the little tweeter up so that the highs project higher, . I'm pretty happy with them for only $25. I've had all kinds of speakers in the past. I have a JL sub sitting in my room but for the price, generic regular speakers seem to do fine for me. Maybe it's because I don't have one crappy one and one really good one so I can compare them side by side, but I'm happy!

 

I have a detailed writeup on Tech with plenty of pictures and alot of suggestions.