There are a number of posts in the archives re how to clean the pot with compressed air and electronic parts spray cleaner. Check the search function.
You might be able to solve your problem for about 2 bucks' worth of spray and not have to mess with an aftermarket hookup.
That said, if the radio now works better, put the money you were ready to spend into upgrading speakers. Best bet on speakers is to take yours out and measure both diameter and depth, then go shopping online with somebody like Crutchfield's (good folks, but sometimes their program for finding you speakers to match your car is significantly off). While you have your speakers out, make sure which ones are 4-ohm and which are 8-ohm ( they should be stamped or labelled on the back of the magnet). Polks and Infinity are good brands, reasonably priced. However, that's just my opinion--check the earch function under ...best speakers... for a variety of heated opinions.
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We have met the enemy and they is us. [Pogo] S70 T5 cop car : Rough Rider suspension, Walmart fog lights, eBay speakers, ambiance by Pall Mall, trim by Le Duc d'Tape, 8-channel THD by OEM amps