Hi all : I had put an aftermarket stereo in the car. But I took it out as I like the stock look. I want to upgrade to the premium sound system. I know earlier radio cassette units had a switch on radio to do just that. The 99's do not. Anyone know how to do this. Or will I have to search on ebay for a unit that was configured for premium. I know I have to get the amplifier unit as well. I guess I would have to ask seller if its out of a car that had the upgraded sound. The 99 units were harmon kardon I believe. Any suggestions. Tks Howard