I have a 1999 buick regal GSE . My radio's cd player and tape are not functioning . I would like to replace with an oem . When i check them out on ebay there seems to be two models. One with the tag "Monsoon" on the cassette door and one with the dolby sign on it . My unit now has just the words dolby on it . Can I interchange them? and also my door speakers say Monsoon on them so im really confused. Plus im looking for a reasource for a diagram for removing and replacing the factory oem radio...how too or instalation guide