1. Take the existing wire bundle out, thread your wire through it, and replace the bundle;
2. Lube the wire ("pulling compound" is available at electrician's supply stores or Home Depot -- it is basically electrically-insulating slime) and try to snake it through the bundle in place; or
3. Poke new holes through the door metal (or rubber grommets) and just run the wires wherever they can fit.

Chain-type stereo stores (Circuit City and the like) will use method #3. A really good stereo store will use method 2 or perhaps 1.

You might be lucky and find the bundle already contains unused wires for the speakers. Get a wiring diagram (call 800.25-volvo, or ask your dealer for a photocopy).

Hope that helps. Good luck.

-- Bruce
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-- Bruce / '82 244 (315k miles!), '86 745, '87 760Ti, '94 854