Originally Posted by shizwrx
will an OEM 05 6 disc fit in my 02 ?? completely plug and play?
In general: If your car's stock radio is double-DIN and the one you want to transplant into it is single- or double-DIN, the new one will fit.
The face of a single DIN is 2" (50mm) tall and 7" (180mm) wide. Double-DIN is two of those stacked (4" tall).
If both cars are 1993 or newer* Subarus then the main speaker/power harness will be plug-and-play.
*Exceptions: 1993-1994 North American Legacies use the older plug; 1995-up are same as other "modern" Subarus. SVXs use a completely different plug (see my homepage for adapters).