Efficient way o fix audio system

[mgrych]

After a few hours of looking around it seems like what should be a simple fix will actually be long and painful. The way these cars are set up, doesn't allow one to simply replace the speakers with better ones as the amp doesn't have the right processing to send quality audio to aftermarket speakers. BSW makes the kit but it only helps a little and is like $600

So what's there to do? Replace the amp, speakers, and subs, and tweeters? well then u run into the issue of the stock amp providing the car with all the chimes, bongs, and dings and other noises and what not, so it can't be replaced?

My car's audio sucks and I don't want to spend 2k+ on ripping the whole thing apart..

Has anyone been successful on a decent budget?