You might want to take your stereo to one of the reputable audio installation centers in your area. These guys do this stuff all day, every day, and have the tools and knowledge to do it right. And usually they are not that expensive. They can do the installation in an hour....it will probably take you two or three hours. You can save yourself a lot of time and trouble, not to mention $$ by having the stereo unit installed by the experts. And any reputable company will guarantee their work.

__________________
1986 560 SEL (159K miles)